According to People, Nikki Reed thinks Rob's lure is because "Rob is sort of feminine looking and I think young girls like boys that look like women".
Oh, Nikki, I'm no "young girl" (27) and Rob is no "boy" (alllllll man!) but he still makes me melt!
However, despite the fact he's *smouldering, Rob is... (don't hate me) "odd" looking - beautiful yes, but in a decidedly odd way!
Letters To Rob explained it best with their post "What is it about Rob Pattinson" - check this excerpt:
Moon: Seriously, what is it about this boy?! Like really what is it?!
UC: I know! I dunno!
Moon: Is it that he played Edward??
UC: I mean, NO! I don’t think so. I mean. It helps, but…
Moon: of course
UC: He doesn’t look like Edward on the Remember Me set. He’s not being Edward
Moon: he’s pretty hot
UC: Let’s discuss this
Moon: yes let’s break down the allure of Rob:
Breaking it DownOk so obviously the physical- he’s tall, good looking, great hair, but he’s not like the hottest man ever, right? Like if I saw him in real life and he was a regular dude…
UC: No. Not Ever.
Moon: I would think he was cute and stuff but I wouldn’t lose my shit.
Personally I think there's some very delicate equation for Rob's hottness along the lines of:
sex hair + bedroom eyes + musician fingers_______________________________ x jawesomenessadorkableness