How does Yedda compare to ask.com and ehow.com?
To add onto that other websites which would make for a more direct comparison to Yedda would be the likes of answers.yahoo.com, blurtit.com and unasked.com
I think the main difference you'll find between all of these is the level of activity of each website and to some degree certain categories of questions will have more or less active users answering questions in them. Personally I've found Yedda to be the most useful next to yahoo's service.