Hey Grinchie! Hey TM!
And from wikipedia:
And on one of those innumerable documentaries that I always forget the name of, a guy explained that the number is used generally, like we would say "a thousand"--as in "Dude, there must have been a thousand of 'em!" or something like that.
Personally, I get excited over correspondences so I was wondering over the number m'self, since there are 72 cards in a Tarot Deck. (22 of those are Major Arcana, and that corresponds to both the Hebrew alphabet and the number of chapters in the book of Revelation.) But the virginal aspect would simply attest to the idea that these would be desirable women, or vessels of purity.
And I think that this less of an incentive than the idea that someone would rather die for freedom than live in a hopeless situation (and didn't I get beat up for typing that before?) but yes, that and the idea that the family of the suicide bomber is promised a monetary stipend is also part of the deal. The Martyrdom bit is just icing...
(Please people, I'm tired. I'm not advocating suicide--suicide bombers--or even virginity as a measure of "desirability" for women--or even logically defending the premise of sex without flesh.)