When Facebook drives traffic to an application, it often append &ref=whatever to the query string. This is useful for figuring out which integration points are working or not. I've figured out what some of these mean. For example:
ref=bookmarks - the user clicked on a bookmark.
ref=game_my_recent - the user clicked on the upper portion of the games dashboard.
What does "ref=ts" mean? It accounts for a ton of traffic. I've viewed source on pages all over common Facebook pages and cannot find a match for ant piece of content generated by any of my applications.
Same question, posted by me on the Facebook developer forum: http://forum.developers.facebook.com/viewtopic.php?id=54866
It means 'Top Search' (if you enter a query into the top, and then click on something, it will append ref=ts