I'm telling you, making a girl jealous may bring her back temporarily, but it's NOT going to last. If you get a girl back by dating other women, she's going to have serious issues trusting your faithfulness and committment to her if you get back together. I mean, if you've only been broken up a few days and you're already dating other women, what does that say about you? Either you're an asshole who's toying with her or you never cared about her at all and you were probably cheating on her the whole time you were together. (Obviously that might not be true, but that's the way alot of women would see it.) Dating other women is NOT the way to get back someone you are truly in love with and want to spend a lifetime with.
And although I usually agree with KRL on most issues, this is one I have to disagree on. That whole bit about "other fish in the sea" is just nonsense. Sure, there are plenty of women to date, but there are VERY FEW that you can actually click with and connect with on this type of level. If you're looking for a real committment and you find someone who treats you well and you have alot in common with, it's WORTH holding on to.
Maybe that bit about making a woman jealous to get her back is fine if you just want her back long enough to keep you in free fucks until you find a new girlfriend, but it's not going to help build a meaningful relationship for those that want it.