That depends on what you're after, its reputation, do they pay you, get people through the door, commission new work etc.
Originally Posted by Tom Kershaw
My comment was really referring to the larger more specialist galleries in the UK and particularly larger exhibitions.
Smaller galleries often don't pay and may be more flexible with shorter time scales, and then there are more democratic spaces. While in Lima, Peru I saw a superb photographic exhibition in a Park - almost everyone stopped to look at the exhibition which was work by many South American photographers. About 5 years ago I had a large exhibition in a Marquee at a canal Boat festival, that had far more visitors in 2 days than most galleries get in a month.