Difference between a Club DJ and a Bar DJ?

In general, more clubs have a cover charge than do bars, so the DJs at clubs get paid higher. But there is also a commitment that comes along with the higher salary, to get people onto the dance floor, which is not always the case with bars. And from my experience, the length of gigs at bars are generally longer than those at clubs, possibly because the music at clubs need to be more fresh and dynamic to keep people on the dance floor, which can be done by regularly rotating the DJs.

I personally prefer DJing in Bars, because generally the environment is more relaxed, and I can play more of the music I like -- US House. When I play at Clubs, since I don't have a big Commercial House collection, I need to be more careful in my track selection. At bars on the other hand, I can be more versatile with my larger US House collection. I've tried playing some upbeat US House at clubs, but quickly realised that it only works if played very early when people are still warming up, or later but with a good dose of Commercial tunes. People often prefer to listen to something they can sing along to, rather than just quirks, beats and an occassional mumble!

As far as skill goes, I wouldn't say either type of venue brings in more skill. In clubs you need some fresh upbeat tunes mixed in reasonably well but quickly, to keep the dance floor active. You also need to have the skill to be able to mix with louder music than you find in bars. In bars on the other hand you need to play more layed back tunes, and long smooth mixes will be appreciated (perhaps with some skillful use of the EQs). But there are also exceptions -- in some bars you can even get away with being a Juke Box! Although long smooth mixes are not necessary in clubs, the day you play like a Juke Box is the day you'll have to start looking for more gigs.

This is just from my experience anyway. Would be great to hear what others think.