That's one of the entries in this article, "Things Women Love To Hear."
Quick: Do you think it was written by a girl or a guy?
Maybe this additional example will help:
“Those jeans look great on you.” This is a polite (and obvious) way of telling her that she has a nice ass.
Cluelessness aside, the article's suggestions aren't entirely off par, but my favorite part is the disclaimer that comes at the end:
Just as important as what you say is how you say it. If you dish up these phrases and don’t actually mean them (which is often the case), you obviously have your work cut out for you if you want her to actually believe you. Work on your style and delivery, and don’t bandy these phrases about without some serious recognition of the power they hold.
OK, blogosphere, it's your turn to talk back.
In relationships, when do come-on lines transform into compliments?