I don't think this situation can really be described as a trick.

The way I see it, the main services publishers provide are distribution, marketing, and to a lesser extent editing. Self-publish or go with a vanity publisher, and you're going to have a harder time getting into bookstores or other content distributors, because you haven't gone through their filters but also because you're not playing the usual game. But that just means you need to establish the book's worth yourself. The typical reader won't be able to tell the difference, but in order to get your book to the typical reader, you need to jump through a lot of hoops that are more or less equivalent to what a publisher would be doing for you. And popularity of course is a vindication all its own (there have been successful self-published books, albeit not many).

Now, if the question was whether it's ethical to claim the status you'd get from being picked up by a major publisher ("I'm a published author!"), then I'd be right there with you. But I don't think that having a vanity-published book in the wild, or even pointing people to it, is equivalent to making that claim.