Chitika ads are what are called 'behaviourly targetted'. That means that they respond to what people using search engines are looking for. In other words, if you search for hotels, then the ads displayed will be related to that. For this reason you can use them along with AdSense.
So if you get a decent amount of traffic from search engines - and especially from North America - then I would suggest trying it out. There are two particular practical advantages to Chitika. The payout threshold is very low - $10; and they pay through PayPal. If you want to be paid by check, then the threshold is $50. So if your earnings are over $10 for February, then at the end of March the money will be in your PayPal account.
As I said at the beginning, I've been comfortably over the threshold over the last few months and it's nice to see the money in your account at the end of the month!
Definitely worth a try!