When I built The Confident Man Project website, I wanted to create affiliate links from keywords in the articles on the site so that I got paid when a visitor purchased a product that I recommended. Rather than inserting these links manually, I wanted them generated automatically so that all I had to do was specify the anchor keywords and my affiliate link.
For instance, when I mentioned Double Your Dating, I wanted that text to convert automatically into a link; just like it did in this article. I also wanted to streamline my link cloaking mechanism. Up until then, I'd been cloaking my links by creating a 301 redirect manually on the control panel of my hosting provider and then manually adding links to articles which pointed to that redirect. This was a hassle, and I wanted to have it handled for me within WordPress instead.
Here were my requirements for my ideal keyword affiliate link plugin, ordered from most to least important:
- Automatically convert keywords in posts into links
- Cloak affiliate links via a 301 redirect so that fraudsters can't steal my commission.
- Redirect accessible externally, so that when a PDF file links to a resource, it goes via the same redirect.
- Include links in the RSS feed too.
- Works with MailPress so links appear in newsletters and work correctly when clicked.
- Avoid hyperlinking from within headings and subheadings (h1, h2, h3, et al).
- Process visitor comments too.
- Generate direct uncloaked links for non-affiliate targets.
- Limit the number of links generated for each keyword so that readers don't get link fatigue and search engines don't consider links spam.
- Always link the first and last occurrence of a keyword in an article.
- Link to other keywords occurrences chosen randomly.
- CSV Import/Export of keyword/link pairs.
- Always match longest keywords so Product is distinct from Product Pro.
- Stealth links that look like direct target links if hovered over so visitors don't avoid them.
- Actively maintained/Recently updated
- Track traffic sources to distinguish links from posts, forums, and PDF documents.
- Rewrite normal links to sites for which I am an affiliate into affiliate links.
- Does it add a trailing slash to the redirection links?
- Reasonable cost for use on 4 sites.
Cloaking Considered Harmful
Unfortunately the powers that be at WordPress.org recently decided that they don't like link cloaking, and all plugins supporting it got removed from the WordPress Plugin Directory. Generally this has led plugin authors to remove the cloaking functionality so their plugin could be relisted, meaning cloaking is now available only in the commercial Pro editions.
My reason for cloaking links is to prevent unscrupulous people from defrauding me of commissions by hacking the links. I also want stealth links so the appearance of my links reflects the site that they land on after the redirection. This more accurately reflects the link target than unusual looking links which appear to point back to my site, when in fact they redirect to another party.
I don't consider this type of cloaking deceptive, and the Terms and Conditions of Use of my site explicitly state that links on my site may earn me a commission if you click on them and end up purchasing a third-party product or service.
With all cloaking plugins removed from the WordPress Plugin Directory, they're a little harder to find; where possible I'll give you links to them below.
Here's an overview of the results in table format:
|Plugin||SEO Smart Links||Ninja Affiliate||Pretty Link||SEO Ultimate Deeplink Jugger-
|WP Affiliate Link Manager||AFLinker||Eclipse Link Cloaker||Instant Word-
|KB Linker||WP Link Engine||Word-
Press Link Cloak
|WP Affiliate Pro||Cross-linker|
|First & Last||No||No||No||No||No||No||No||No||No|
|CSV Import & Export||Yes||No||Yes||No||No||No||Yes||No|
- Yes: is supported directly.
- No: is not supported directly or is difficult/inconvenient.
- Pro: is supported by the commercial version of the plugin.
- If there is no free version of a plugin, all Yes answers will read Pro.
- Opt: means it's optional.
- Bold: I verified it myself. Regular: I relied on documentation or feature claims.
- Blank: I didn't determine whether this requirement is supported or not.
- Cost is in US$.
SEO Smart Links Pro
I chose SEO Smart Links Pro as the best fit for my requirements. In addition to the link generation requirements it also creates hyperlinks that I want between articles on the same site automatically, so I would use it anyway. If you don't need link cloaking or redirection support, you may get away with the free edition SEO Smart Links.
The plugin supports CSV Import/Export and allows multiple keywords for the same target link. The author changed the way it handles the keyword separator to make handling links in a spreadsheet easier in response to a request from me and gives excellent support.
This is the most expensive option but it's one of the best wordpress plugins I've found and has the most important features for me. You can get similar functionality for free by combining the free SEO Smart Links with another plugin like Simple URLs, GoCodes, or Redirection plugin; but this means managing your link URLs in two places. Blah.
Runner up is Ninja Affiliate from MaxBlogPress. It meets most of my requirements, but can't handle direct links. However the free edition of SEO Smart Links can, so I used these two plugins together until SEO Smart Links Pro was released.
It has a few annoying quirks: It doesn't avoid headings. You have to give every Ninja Link a name, but this isn't matched as a keyword so you have to enter this information twice. It would also be nice if it accepted direct links to the target site without the redirection by leaving the Ninja Link box empty.
The Ninja Links icon the plugin adds to the TinyMCE toolbar is unnecessarily large, and causes a conflict with MailPress 5.0 which breaks the mail editor. To work around the conflict, visit Keywords To Ninja Links Options → Troubleshooting and select Don't show Ninja Links drop down in write post page.
Pretty Link Pro
The free Pretty Link plugin creates redirection links but you need the Pretty Link Pro edition to get keyword matching. It seems kinda klunky compared to SEO Smart Links or Ninja Affiliate, but has most of the features I was looking for.
I based this evaluation on Pretty Link version 1.4.50, which was the last version before the author was forced to remove link cloaking from the free version by the WordPress extensions anti-cloaking policy.
SEO Ultimate Deeplink Juggernaught
The Deeplink Juggernaught module of SEO Ultimate can create links automatically, but it can't do the cloaking redirection. This can be overcome by using the Redirection plugin, which I install anyway to handle any permalink changes automatically. Combining these two gives you a free solution almost equivalent to SEO Smart Links Pro or Ninja Affiliate, but means entering the redirection URL in two places which is inconvenient and error prone.
This plugin can also generates automatic links to other articles on your site similar to SEO Smart Links, which is supposed to help with your search engine optimisation.
WP Affiliate Link Manager
Although it lacks some of the features I was looking for, WP Affiliate Link Manager handles all the basics of managing, redirecting, cloaking and generating affiliate links from keywords. It's also the cheapest of the commercial plugins. However it has a nasty habit of changing the capitalization of the keywords in the articles, replacing them with the capitalization from the link manager.
This is a commercial plugin and they generously sent me a free copy for the purpose of this review.
AFLinker has some extra features to avoid getting penalized by search engines. The free version does everything the pro one does so you can try it out, but it includes includes branding and sponsored backlinks so it is only recommended for testing.
It separates the affiliate redirects from the keyword matching so you can have multiple keywords per affiliate link, like with SEO Smart Links.
Eclipse Link Cloaker
Eclipse Link Cloaker allows you to selectively enable cloaking on explicit links with a comment token. It seems to do a good job. It always adds a trailing slash, which I'm not a fan of.
This is a commercial plugin and they kindly sent me a free copy for the purpose of this review.
Instant WordPress Link
Instant WordPress Link does the basics, and can also generate links to ClickBank products randomly chosen from a chosen category based on the specified keywords. This could be handy if you're a ClickBank affiliate. It also has options to generate link tooltips, and those annoying link popup ads that I hate.
This is a commercial plugin and they kindly sent me a free copy for the purpose of this review.
The price is right, but BlogMechanics KeywordLink hasn't been updated since February 2009. It does the basic linking job well, but lacks the more advanced features I need. I recommend the free SEO Smart Links plugin instead.
Similarly, KB Linker just does the basics for you and hasn't been updated in ages.
WP Link Engine
WP Link Engine looks like it would handle the basics pretty well. It also has the ability to use geolocation to point visitors to the most relevant target affiliate site based on their location, which I haven't seen in any other plugin. I didn't install it, so I never got to evaluate it thoroughly.
WordPress Link Cloak
I really didn't evaluate WordPress Link Cloak. The sales copy looks a little out of date and is big on internet marketing hype rather than features.
WP Affiliate Pro
All the support links on the WP Affiliate Pro sales page are broken, which doesn't bode well. I didn't evaluate it properly either.
Another basic keyword linker is Cross-linker. Also hasn't been updated in a while.
First & Last: A Missed Opportunity
People pay more attention to something the first and last times they see it. Converting every instance of a keyword into a link creates a spammy effect, so many of these plugins have the ability to restrict the number of times they will convert each keyword. The better ones have an option to randomly choose which instances to convert. But none of them yet offer the optimal strategy: always convert the first and last instances, plus a random selection of those in between until they've made up the number requested.
So here's my challenge to plugin authors: who will be first to support this feature?
Hiding Affiliate Links From Search Engines
Joost de Valk points out that it's a good idea to hide your affiliate links from search engines by including this in your robots.txt file:
User-Agent: * Disallow: /resources/
Replacing resources with whatever base you use for your links. Since robots.txt is generated by WordPress if you don't have one, these plugins could do this for you; none of them are smart enough to though, yet.
Not So Stealthy
I didn't find any plugin that could generate redirected affiliate links which look just like a normal link to the target site, at least when viewed with Firefox. That's probably because evil people would use such a feature to make links to their malware site look innocuous too, so I gave up on having this.
Rewriting Non-affiliate Links Into Affiliate Links
None of the plugins mentioned above could do this, but it can be done with:
- VigLink vigilantly turns any regular link for which there is an affiliate program into an affiliate link, at the expense of some of your commission.
- Amazon Affiliate Link Localizer turns Amazon links into geolocated affiliate links.
Other Related Plugins
These plugins didn't quite come close enough to meet my requirements, but are in a similar vein:
- WP SEO Master has an Autolinker module, but doesn't help with affiliate link management and doesn't appear to be maintained. I got “Plugin could not be activated because it triggered a fatal error” when I went to activate it.
- Affiliate Hide is a simple free solution for hiding affiliate links on a single page. It doesn't do the global keyword search I wanted though.
- Simple URLs and GoCodes do link shortening/cloaking, but not the keyword matching.
- tagwords by tagsoda matches tags instead of keywords.
- Skimlinks, 123LinkIt, and ViralURL all generate keyword matches automatically based on advertisers settings on various affiliate networks. You can't easily add specific programs with keywords you want and they take a cut, but they're very low maintenance if you have a lot of content already on your site.
- Link Hopper only handles the redirection side of things.
If you're aware of an automatic link generation plugin that I've overlooked, please leave a comment to let me know about it.
All but 4 of the links in this article were generated automatically by SEO Smart Links Pro. Can you guess which ones?