Alert Types
There are many types of alerts that you can receive based on different actions performed around this site. These are the current different actions that cause an alert to be received:

Added to Buddies

This alert type is received whenever another member of the site adds you to his/her buddy list.

Quoted in a post

This alert type is received whenever another member of the site quotes you within a post anywhere on the site.

New reply from a thread

This alert type is received whenever another member of the site replies to one of your activities threads. This alert is only received for the first new post to the thread rather than being duplicated for each reply.

Mentioned in a post

This alert type is received whenever another member of the site mentions you within a post anywhere on the site using MentionMe Twitter-style mention tags.