Joe, they are real, many are very reliable re-bloomers, depending on the zone you live in. (I would caution you from buying any from a box store though, often misslabled) I would guess that there would be several that would re-bloom in zone 7, there are only a few that will make it before frost in my frozen part of the world.
@Arlyn is our resident re-blooming expert on here, maybe he will weigh in on this question. He lives in Illinois, and has had success with rebloomers there.
They do require a bit more fertilizer after the first bloom to build up for the next bloom season, but beyond that I don't think they require much different care then regular ones. The white one Immortality is a very reliable re-bloomer for me here in Wisconsin.
