...could it be their international sales? To hear people talk, you'd think the American economy is unraveling, but iPhone and Mac sales are doing better than ever. (?)
Because it's luxury spending
Because some types of spending, like gambling, goes up as the local economy gets worse
Because "the economy" is not homogenous, there are always people who do well, and people who do not so well. "The Economy" doesn't buy phones, people do.