"Faire La Bise" or "to kiss" is as important in French culture as saying Hi and Goodbye
La Bise is in fact institutionalized In France. Refusing to accept a kiss might be seen as an indicator of antipathy between people. However there are quite a lot of rules in the art of "Faire La Bise" in France. It depends on the situation (being formal or informal - it's a norm among friends and relatives, but at work mostly among closer colleagues), on the age difference (usually the older person is supposed to initiate the kiss). The number of kisses also varies in the different parts of France.