jools:
I have found it rather disheartening when it drops downwards again!
I hate to tell you, Jools, but the favorites number is a dynamic number and I have seen it move both ways. I think some do use it as a temporary bookmark to remind them to return and read the story, and once that is done, it gets removed----and your "favs" count goes down. Nature of the beast I guess. (Hopefully they left a comment before they deep-sixed the favorites marker)