So how much do bonus promotions net a pokersite?

[Exsubmariner]

I have had my rakeback trackers only measure $30 MGR after clearing a bonus. I was curious to know that if there is so little revenue generated, what is the incentive to offer a bonus? Then again, I am a winning poker player and actually will collect the bonus. Will most players go broke before finishing the promotion? And also, I imagine there is that whole denying your competition of collecting rake while their regular players are playing your promotion.

Anybody got any ideas/facts about the answers to my curiosities?

[thing85]

I would imagine one factor here is that many players who deposit $50 and gamble at 2/4 or 3/6 limit (or $50 NL) never clear the bonus. Also, it brings in traffic to the site, which of course is necessary for them to keep up a popular image and keep the regular players from leaving and finding sites that have more players.