I probably would. 20 million? Get real.
I would think on a website dedicated basically to sex that there would be a little more awareness about sexually transmitted diseases and what they actually entail.
A very large portion of the population has some form of herpes. Most people show no symptoms or have very mild symptoms, only having one initial outbreak.
Additionally, you can get it from simply kissing another person while the virus is shedding, which doesn't necessarily have to happen during an outbreak.
As far as non-curable sexually transmitted infections go, herpes is pretty low on severity list. It's also fairly treatable.
So, yeah. When you get over the whole puritanical "ew it can be transmitted by sex, repent!" factor, 20 million sounds like it might be doable.