I've used Priceline for years for hotels, in a variety of cities both domestic and international. Always personal travel.

I've always been at least happy with what I got, and occasionally downright delighted. Besides, I like the fun of bidding and the surprise.

But I agree with prior posters that research is vital. Betterbidding (bidding results, hotel reviews, searching on city name, calendar of wins), and also checking rack rates and the usual suspects like kayak and venere.

Some areas are more difficult for bidding than others. I've had to use other sources in Italy more often that not.

I've been successful a few times with auto rental although I don't use it much. Have never used air, but know people who have and are happy with results.

Romelle