Gene: this doesn't just ping alexa. It pings a service (pingomatic) that pings all of their supported search engines and all.
However, this addon just didn't work for me.
1. I installed it properly, placing the files in the correct folders. No apparent error.
2. I modified the /DataWriter.php script to log whenever the ping function is called
3. I created a thread
4. The log didn't show any data.
5. I replaced the source code of DataWriter.php with random garbage
6. Created a thread again. Nothing happened, not even an error, the thread posted normally.
I think this addon might not be compatible with the latest version of XenForo ?