Pros
Cool; (duh, it's Facebook!). Great resources, lots of 'candy' (e.g. free food, parties,...), super autonomous (do your job anyway you want as long as it gets done. Have a trip to Menlo Park; no problem, etc...). Great impact (did I mention the billion+ people using this thing?). Great culture (when applied - see notes below). Great benefits (salary, shares, medical, 401k,...)
Cons
Bad work / life balance - you better be jusr out of college with no wife/husband/partner; nor any children. They do not know how to deal with senior people. Managers are just employees who do more work; they do not have time or the need to help out. I have seen a few people get thrown under the bus by the boss - why defend your team when Menlo Parks complains because they do not know what you are doing; fix another task and get new employees.
