What does this really mean? How should you use this module?
1) Create a freetagging vocabulary called "Tags" assigned to the content types on which you'd like to display the "Similar" block.
2) Enable the block called "Similar entries from the Tags vocabulary".
3) Add keyword tags to the content.
Done!
Now when you go to the page for a tagged content item, a block will show up displaying other content in descending order of common tags (terms).
You may be interested in comparison shopping: Comparison of Similar / Relevant by term block modules..
Similar By Terms 2
Similar By Terms 2 is a complete rewrite of Similar By Terms as a Views plug-in. It offers much more flexibility than the original version. The module provides a default view which exposes a block which should function exactly the same as Similar By Terms 1. However, Views can be customized or cloned to add different fields, filters, output formats, or any of the good stuff we've come to expect from Views.
Find complete documentation for Similar By Terms 2 in the README file or visit the GitHub repository to read it online.
Before upgrading from Similar By Terms 1 (SBT1) to Similar By Terms 2 (SBT2) please read the upgrade instructions. Since the versions are so different, you will need to enable and configure the SBT2 blocks manually after upgrading. If you are familiar with Views, this is a very easy process.
Similar By Terms Drupal 7.x-1.x
7.x-1.x is based on Similar By Terms 6.x-1.x branch and not the 2.x branch so no views support. Sorry I started the 7.x branch before Jeff started working on the 2.x branch. 7.x-2.x will be views based and based on Similar By Terms 2.
Beta 1 is released this is the 1st version that I have trusted on my production sites. It still needs some testing but I haven't had any issues running it on my production sites.
Issues
As with all contributed modules, when considering submitting an issue:
PHP 4 and MySql 4
Due to end-of-life on PHP4 and MySql4, we no longer actively support either of those products. If a problem arises, we will make an effort to work around it, but will not make a guarantee. Drupal 7 will require PHP 5.2.5 or higher and MySql 5 (or Postgres 8); if your host is not at these levels yet, please encourage them to get there ASAP.
The module was originally created by Jeff Robbins and sponsored by Lullabot.