I was going to post this in the original Susan Boyle thread, but that’s on to four pages now, and will probably begin to wind down pretty soon.
But to put Susan Boyle in context, here’s one of my favorite performers, the very successful Mary Coughlan.
Point being, I don’t think Susan Boyle’s looks are even relevant in this whole phenomenon. The key thing is the whole “never been kissed” angle. Coughlan’s singing is full of sex: she sings a sultry blues that makes it pretty clear the broad’s been around the block a few times. Boyle’s affect is quasi-Aspergerish, to some extent: she’s clearly never been laid, never mind kissed. I think her whole persona is likely to change once she becomes a little more shall we say worldly.
Of course, I could be entirely wrong. Will be interesting to see.
(ETA: cricetus covered it better than I could’ve.)