kauppias I am also on a waitlist. So you have to keep in mind that there are others who are also on that list. You are competing wit others who may have paid a higher fare then you and also a lower fare then you. So hopefully you have paid the highest fare type and your chances of an UP will be better.
And based on your fare type you do get free seat selection but they are also charging a nominal fee if seat selection is not included in your fare type. Most of their flights are short enough intra Europe so you will survive as you mentioned in your post. I will not bid as I know that my flight is over sold in Y. Flying FRA to ATH and onwards to KOS. Good luck to you.