Everything.
The CEO is an empty-headed puppet with Glenn Fogel pulling the strings. He wouldn't know what to do with an original thought if someone handed it to him. He stands up at meetings telling everyone how "wonderful" everything is, when everyone knows that they are not. Not one word about what the company is doing to overcome the struggling areas or changing to improve the organization.
The CTO, who has been there 2 years now, has completely disassembled the technology department, wiped out all job satisfaction that anyone has had, and created an environment where no one wants to be there. I watched as new developers, filled with energy and excitement became beaten down and discouraged, leaving the company after only 1 year of service. This guy is an inflexible tyrant that doesn't care what anyone on his staff has to say unless it's an "ata-boy boss!". If you're going to work for this idiot, bring plenty of chap stick.
From a company that once had employees happy to be celebrating their 15 year anniversary, to one where most people don't last more than a year, Priceline has become the kind of place any decent talent should avoid like the plague.
Turn over at Priceline is around 25% on a good year, some times much higher. Most folks still working there are looking for "the perfect job" before leaving, allowing for the rite mix of technology, compensation and work/life balance.