spottiness

One reason may be that the vast majority of young (very fertile) pretty women are not looking for dates online; simply because they have plenty of choices around them and therefore don't need to look in the virtual world. Males follow women in that category, wherever they are.

The author meant the users of the service, because it doesn't increase significantly the chances of meeting someone for a long term relationship, otherwise there would be less involuntarily single people out there (that's Greenspun's argument).

Our site "Spottiness.com" may serve you well, in particular the "Blackspot" section. We help people communicate anonymously and allow targets to respond. If your anonymity is paramount, you should be careful with your writing style and other clues.