Interesting question, let me throw out an observation that inverts things a bit. Apologies if this is off-topic.
First, I'm a guy, nothing to speak of in appearance, told I look a little like Tom Hanks. I don't turn heads -- typically. Except... about once a month (I can never predict when), it seems that every female I run into for a day -- work, shopping, whatever -- takes a very flirty interest in me. It's very pronounced and almost magical. These are women ranging from late-teens to mid-forties, from all walks of life, in all manner of venues. There's nothing common about them except that they are female, so it isn't the "sorority-house-synched-cycle" phenomenon.
I'm not sure where this is coming from. I assume it's some pheromone I'm giving off, but it isn't predictable (i.e., cyclic) nor can I isolate it to anything particular I'm doing (working out, shower frequency, etc.). But it happens enough to be noticeable and intriguing. I just wish I could bottle it! :->
(For the size queens/bulge watchers here, let me unfortunately assert that I'm pretty sure there's nothing to, uh, arouse attention in that area -- I'm average in length, a little above average in girth, and pretty unimposing unless I'm erect. Most of the guys here seem to be monsters.)
Kevin