It was about consumerism and sex and sex as consumerism.
I found it a decent way to burn half an hour or two if my suitemates were doing one of their incessant marathons and I was in the mood. It actually had some pretty smart writing and humor and some really genuine emotional arcs - not the kind of characters or story focus I seek out, but interesting enough when it's there. I can see buying, I dunno, a $12 trade of an eight-issue mini of a Sex & the City-style comic featuring characters I know and care about written by a witty author who understands and cares about those characters in particular and what they in particular would say or do in the situations they're recounting to each other.
The funny thing *about* Sex & the City, though, is how deeply failtastic and not particularly Sex & the City-like things that are described as appealing to that sensibility usually are. Kind of like how "Eragon is the next Lord of the Rings" or how people refer to films or comics as "mature" when actually they mean "written specifically for an extremely adolescent mindset." (Or even more comic-specific, it's similar to the way WATCHMEN killed all sense of decency in the industry, because people keep trying to imitate it without understanding what Moore's writing actually was.)