As we all know, menstrual cups don't get anywhere near as much publicity as they deserve. Don't know about your country, but here in Australia you can't buy cups in the supermarkets or chemists and there is zero advertising. It seems like no one even knows that they exist. So how do we make menstrual cups go viral? - Toilet paper!
Every time you visit a public toilet, bring along a pen and after you've taken the toilet paper you need, write a very quick one-liner about menstrual cups on the next square of toilet paper for the next user. A few examples:
"Menstrual cups!...
- look them up
- never using a tampon again
- no more stinky, soggy mess
- Kotex/Stayfree/Libra must hate me
- you'll thank me later
- visit menstrual-cups.livejournal.com
- spread the word" etc.
It's quick, simple, it doesn't make you a vandal, it reaches beyond your immediate circle of friends/family and it's anonymous which is great if you're not comfortable ranting about periods in person. And because toilet paper is probably one of the weirdest forms of communication, it's not likely a reader will forget how they found out and if they become a happy cup user too, there's a chance they'll be tempted to spread the word in the same way, hopefully making it viral.
Personally, all I needed was to stumble across the term "menstrual cups" and it was enough to pique my interest and do a bit of research and ultimately become a happy cup user. Of the people I've mentioned them to, curiosity seems to be the most common reaction so I think that simply getting the term "menstrual cups" out there in peoples' awareness can be quite powerful.
So go forth and start scribbling!