What does the number that appears in the start roll over mean?

That number that appears over your star is your rating. 100 is the highest number. I guess you have a very good rate to have 90. It is like an award that you are a good respondent. It does not have much direct effects but it is something to be proud of since not all reached that rating.

That's the myLot reputation, explained in this FAQ http://www.mylot.com/o/faq/faq11.aspx

When you roll your cursor over it, it says your myLot reputation, which I think is how people in here see you. Wehn they are responding back to your discussions that you start here, or the discussions you respond back too, people (like me), will rate you. The more "+'s" a person gets the higher their reputation is and the higher their Star is. That is why many of us will rate each discussion in hopes of helping the others in here posting to help them see where they might need or want to improve on as well. Hope this helps some for you, and wishing you the Best.

This is our ranking or our collection of pluses '+' (ratings that people give to our discussions). Our star rating increases by 1 point whenever the number increases by 10 points. I guess mylot pays more for people with a higher star rating. & it goes down when people mark "-" to your comments or questions. my personal experience was strange, my ranking went down by a few points the week i was inactive.( may be consistency also has a say in the ranking)