Ask her out as soon as you can after building rapport

[GeeMale]

Because if you get rejected(she's married, bf, 'busy' etc) than you'll be feeling dumb you waited all this exciting time only to waste the excitement energy ..

And even if she isn't you kind of wasted time that you could've been on 1-2+ dates already.

Letting time go by from when you first met a chick that showed interest ...kills the intial attraction

 

[touma.akagi]

Absolutely, my guy... you ask her early so that you know whether to spend any more time. The petty ones will reveal themselves to be so when they act all offended that you asked her.

If nothing else, "we should do something sometime" and ask around a week later