I can't remember too many first dates that didn't lead to a second date. In truth, how can you really know whether you're interested in somebody after one date? After one conversation for maybe an hour or two?
Too many people are so shallow these days that if the chemistry isn't insanely instant and the attraction is not "I want to rip clothes off right now" and the jokes aren't quite "LMAO" enough then the first date is just "meh."
Not to mention, I thought first dates were more like introductions/ice breakers? I don't even really count first dates because everyone can be cool on one date. Let's see how cool a chick is by the fourth and seventh date. Let me see how she acts after she relaxes her representative.
Peace