I jack off on webcam essentially all the time for various women (provided they have a webcam as well). Even girls who profess not to like it seem to enjoy my shows, if only because I do it differently.
There are tons of guys online willing to show off their cock for free, practically begging women to watch them. A couple of female friends of mine have told me about being overwhelmed with requests to look at a man's cock.
I don't really understand the point of going HAY WANA C MY DIK and then jacking off, asking if she thinks it's big, and going through all that trouble like it's something serious. On a webcam, since the girl can't actually do anything serious with the cock, it's essentially taking the cock out of an intimate context and displaying it in and of itself. A cock, by itself, is a size-changing hardness-altering darkly-colored tube attached to a thin skin sack with balls inside, and the entire apparatus exists to pee and shoot white stuff. It's anything BUT serious.
And so, I show it off as a plaything, something silly that you can appreciate without being horny or being particularly into the whole webcam thing. In other words, while I'd love to turn a girl on with my cock, making her laugh is a main goal as well. Judging from reactions I've received, I think this is a good way to go about it. The problem arises that once I've given a show to a lady, trying to entertain her again gets more tricky. Good thing girls tend to appreciate watching me slowly stroke my cock even after I've ran out of cock stunts and tricks!
But to answer your question, Sharp8008, from my experience anyway, yes, girls do like to watch guys jack off. The problem for guys is that girls, again from my experience, aren't fond of being repeatedly asked and begged to watch.