Details about eharmony operations from job postings.
If you take a look at Match.com, Spark networks and yahoo personals they are all about the same in terms of operational costs. No one other than plentyoffish can support 350 million pageviews a month for under a million dollars a month. That only covers the cost of developers, tech people and hardware/hosting!
Many people look at plentyoffish and see the fact that its a site with a ton of traffic as the highlight and major accomplishment. I see my greatest accomplishment as developing a way to serve a billion pageviews a month off only a handful of machines at next to no cost.
At the end of the day, my infrastructure and the fact i have no employees is my greatest competitive advantage. There are other free sites now, with 10-20 employees each and 1/20th to 1/30th my traffic. Even with free/paid hybrid models I can’t see any of these sites generating enough revenue to reach profitability and achieve scale.