while i agree this can be a pretty good way of going about it, there are problems. if you just ask her outright, she has to make a decision whether she is interested in you based on what she knows about you, ie nothing. yeah sure, you get points for being confident, in most cases big points. and sure, if your devastatingly attractive like me (of course ;p) then you will probably get a good reaction.
however, if you dont look like what shes looking for, or shes one of those girls who actually cares what youre like, she might decide shes not interested. then you will have a much harder time of convincing her that you are the true man-god that we all know we are!
so in summary, i think it does work, but not every time. you could end up saving alot of time (with either a positive or negative result) but you could also give yourself an unnecessary disadvantage. unless im really on a high vibe id game her a bit, let her know how awesome i am, and then tell her i wanna fuck her in the ass!