Pros
Expedia is the most fascinating and diverse place I've worked, my daily work brings me into contact with employees all over the world from whom I have learned (and am still learning every day) so much about the world we live in, about how people buy travel, and learning new skills from many different specialist in many different areas. The culture is friendly and helpful - you feel like you can approach anyone, even senior management, and find out whatever you need to know. Generally, the work ethic and atmosphere serves to encourage and develop you and those around you.
Cons
Things change frequently with the org structure - a reflection of the changing and challenging market, but also a 'no let up' approach from management. This, coupled with working with people all around the globe can lead to burn out if you're not careful - taking calls from ridiculously early in the morning to very late at night, just to be able to get that bit of information you're after in order to keep afloat in the job. Upper management may not look out for you on that score - so personal resilience is key in order to look out for yourself yet still manage to drive the results necessary in your role. There's an underlying feeling of 'don't expect to be able to move to part-time hours and expect to keep your career prospects' - could be particularly challenging if you are a new mum.