This, I have to add that especially if it's a new acquaintance, that waiting is the best thing one can do. if I just met a lady and talked to her once on the phone, but then she called me multiple times soon after, if anything it would be a bit off putting, and depending on how many times, could downright scare me away.

on the positive side of waiting for someone to get back to you, it leaves an air of mystery there and if there was any interest initially, it will sharpen their curiosity to just let them be the one to initiate.