Some of my best players have come from free no deposit promotions. Im not sure about that poker room but I have referred players to atlantic lounge casino, casino classic, and blackjack ballroom using the free no deposit bonuses and some of these players have earned me thousands in revenue.
$10 free in a poker room probably wont generate you any revenue because many poker rooms don’t take more than a few cents rake unless the pot is $10 or higher but your players that you refer will have a chance to try out the poker room and if they like it then they will deposit again and again. I say go for it.