Paying for Demos?

Why are we paying for so many demo events this year?

It seems like every dealer I talked to told us that their game was playing in one room or another, but cost a generic this year.  Why was that?

Was that Origins?  or the dealers?  It doesn't make sense to me for them to charge us to try a game we might buy.  Especially when there are fewer of the dealers again this year, its like they should be dragging us in to play their games.  The one that sticks in my mind the most is a d and d minis (2 bucks, yeah, but you don't keep anything, it slike you are teaching me this for 2 bucks) and Mutant Chronicles, only scheduling demos every two hours and then chargin us.

Help me understand this marketing ploy?