After a user reads a post on your blog, you want them to read another, right? Make sure that a list of similar posts is around with a related posts plugin.

There are lots of related posts plugins out there – which should you choose? I’ll be reviewing three related posts plugins -  Yet Another Related Posts Plugin, WordPress Related Posts, and Similar Posts.

(By the way, if you don’t feel like reading all of this, just scroll down to the end of the post and I’ll tell you which plugin wins and why.)

Yet Another Related Posts Plugin is up first. I installed the plugin and was immeadiately confronted with a few PHP errors. This text was showing up under a post:

Great first impression, eh? I’m pretty sure that I could dive into the PHP and find out what was causing this, but, for now, I’m just going to see if changing any settings in the YARPP options page will help.

The YARPP options page is telling me a few things that I have to do to finish installing it:

1. Rebuild the cache
2. Copy the files in /wp-content/plugins/yet-another-related-posts-plugin/yarpp-templates to /wp-content/themes/gulati (the directory of my theme)

The plugin provides a simple interface for rebuilding the cache, so that is a fairly easy step. The other step is a little more complicated, but still not difficult.

Just do exactly as the plugin says – copy the files from one place to another.

If you’re still getting include() errors, try this:

1. On the YARPP options page, check the box for Display using a custom template file NEW!. Scroll down and hit Update options.
2. Do the same, but this time uncheck the box. I found that it wasn’t really necessary to use a custom template file.

For me, this fixed all of the errors. The plugin is now displaying related posts under each of my blog posts. The results seem to be very good – but let’s not worry about that now. I’m going to compare the results of each plugin later.

WordPress Related Posts is up next. This one installed easier. After unzipping the plugin and activating it in WordPress, nothing happened. I found that if you wanted it to display posts, you either had to add a function in one of your theme files, or check the box for Auto Insert Related Posts on the options page.

WordPress Related Posts looks a little better than YARPP at this point. I would probably be more likely to click a link created by WordPress Related Posts right now – but that’s not something that can’t be easily fixed. YARPP is a dynamic plugin, so I can make it look however I want. Unless you’re looking for a plugin that looks good out of the box, I would still stick with YARPP.

YARPP also has much better results than WordPress Related Posts. I have both plugins running right now so I can compare them directly. Posts that are shown by WordPress Related Posts aren’t even related in some cases.

Similar Posts is the final plugin that I’m going to be testing. After unzipping the plugin and activating it, I’m starting to get errors again. This appears on the WordPress plugin page:

I guess that Similar Posts wants you to install this ‘post-plugin-library’. That’s pretty annoying, you have to install a plugin for another plugin to work.

The Similar Posts plugin provides a direct link to the ‘post-plugin-library’ on its option page, so I guess that that’s a plus.

After the Similar Posts plugin is installed and working, you have to activate it on its option page. Head over to the ‘Similar Posts’ page under ‘Settings’ and then to the ‘Placement’ tab. Under ‘Output under post’, change the select for ‘Activate’ from ‘no’ to ‘yes’. You should be getting similar posts under your blog posts now.

Comparing All Three Plugins

Now, let’s go back and see which plugin is the best.

Installation – The easiest plugin to install is probably WordPress Related Posts. It worked right out of the box – all I had to do was enabled the plugin and then tell it to show posts automatically.

Customization – This one is a close tie between Similar Posts and YARPP. I think that Similar Posts is a little bit more customizable (it has more options), but YARPP has a much better interface for customization. Maybe the options that YARPP provides are better than the ones that Similar Posts provides, too.

Results – This is probably the most important category. YARPP is the clear winner here – it provides the perfect related posts.

Winner - The winner really depends on what you want to do. If you want a plugin that you can setup fast, go with WordPress Related Posts. If you don’t mind taking some time to get things rolling, go with YARPP. I don’t really recommend Similar Posts unless you really know how to use it  (or if you are already using it).

Download Links

WordPress Related Posts – http://wordpress.org/extend/plugins/wordpress-23-related-posts-plugin/
YARPP – http://mitcho.com/code/yarpp/ (I used version 3 BETA)
Similar Posts – http://rmarsh.com/plugins/similar-posts/

Thanks for reading! If you agree (or disagree) with any of my decisions here, please leave a comment. I look forward to hearing your thoughts!