I try my best to keep this page as up-to-date as possible, but sometimes it's not (like, when I finish a new version at 2:am and get too tired to update this accordingly). So it is recommended that you check RD WordPress Codex page too, just to be on the edge.

Referrer Detector is a plugin that displays a greetings to users who come from various internet sources (known as referrers). For example, you may want to welcome Diggers with a message that reminds them to digg your story, or you may want to ask Del.icio.us users to bookmark your post, and so on.

Not only about a cool greeting box, it greatly helps to more efficiently interacts with your readers and build a better relationship between you (your website) and them.

This plugin was inspired by Thaya Kareeson ’s WP Greet Box plugin, a great plugin with the same purpose.

Installation:

1. Download the plugin
2. Extract into a folder
3. Upload the entire to wp-content/plugins/ directory of your WordPress installation
4. Enable it via Plugins panel
5. It should now work out of the box. If you want to tweak a bit, head to Settings->Referrer Detector

Features

• A pure AJAXed admin interface with elements tidily divided into tabs. Entries can be added/modified/(de)activated/deleted without the need to reload the entire page, or even with just one click. Starting from 3.2, there are even bulk actions!
• The greet box position can be set to before, after, or (starting from 3.2) both before and after the post. A custom tag can also be used in case you don’t want to show greetings on every post.
• Users can also put a tag (<?php if (function_exists('referrer_detector')) referrer_detector(); ?>) into the template to show the greet box anywhere of choice.
• Excluded URLs can be specified in order to hide the greet box from specific users (like ones from Google Reader).
• A * wildcard character can be used in both referrers and excluded URLs. For example: google.* will apply for all localized Google domains.
• Multiple URLs can be merged into one entry, seperated by commas. For example: del.icio.us,delicious.com.
• Ability to include WordPress attributes like url, title, author, category etc. into the greetings.
• A STAT panel to get data reporting about the visitor statistic.
• Many installed-by-default entries (which can be restored anytime with one click). Upon installing, you will have these entries available:
  1. 9 rules
  2. Del.icio.us and Delicious.com
  3. Digg
  4. Gizmodo
  5. Google Search
  6. Lifehacker
  7. Live Search
  8. Reddit
  9. StumbleUpon
  10. TechCrunch
  11. Technograti
  12. TechRadar
  13. Twitter
  14. Yahoo Search
• Compatible with caching plugins, since the core is written and run in JavaScript which is normally not cached.
• [NEW in 4.0] Automatically detect user’s country and display the localized greetings (if any).
• [NEW in 4.0] Ability to backup and restore entries, excluded URLs, and options, very convenient for transferring between sites.
• Optimized OOP code allows extreme readability and easy modifications for other plugin developers.

For FAQ, screenshots, and other notes, please head to WordPress Codex.