You're just some random dude number 851291 that bugs them to ask for their number.
Think about how you feel when you go grocery shopping and this jerk approaches you to ask you to sign up for their fucking credit card. After the 1000th time, you're just had enough. It doesn't matter how good the credit card is. You're just tired of hearing it. Or when you're walking downtown and this god damn animal rights group dude approaches you to ask for donations. It's kind of like that.
While you're trying to look confident, the girl is thinking "god dammit, not another one. What do I have to do to drink my fucking coffee in peace?"
You got to get to know the girls. By just talking to a random person in a coffee shop you're really giving yourself a wall to climb over.
Maybe a bar at 2 AM, that's different. If she's got that nice short skirt with a little slit on the side and is wearing 50 pounds of makeup and false eyelashes, then yeah. If she's on her break for work and has 15 minutes at Starbucks and it's the only time of the day she gets to relax and you're intruding on her space... yeah...
Hard world for a guy. We gotta compete. Nothing new ---