I'm not sure exactly what Gears of War 2 designer Cliff Bleszinski has been taught about women, but according to him, videogame betas are like scoring with a girl and then throwing her away. Do you not follow? Allow Clifford to explain:
"A beta is like hooking up with a girl just to say, 'Yeah, I fucked her.' I know that sounds crude, but it’s the honest-to-God truth. Once you play a beta, you can check it off your list - you can say, 'Yeah, I played it.' Then you might not feel motivated to get that initial cherry popping from the proper, final game."
I personally don't know any men who check women off their "list" after a quick shag, but that's usually because I don't hang around with douchebags. Still, that's an odd analogy being employed to make a suggestion that actually has some merit. Of course, a good beta will make the player want to come back for the full product, just like a woman who won't take it up the arse on the first night. Jesus, now he's got me making sexist metaphors.
As for demos, Bleszinski is equally as contemptuous, stating that we wouldn't have had Gears 2 "until February of 2009" if Epic had spent time pulling one together. He had no sex-based reference to make for that subject.