He uses 2 cents per unique visitor as the main formula for free sites relying on AdSense for their revenue. If you’re paying for visitors (say $5 per member), “it’s impossible to build a free site on mass advertising.”

Sure, we’ve all read about Markus Frind running the free Plentyoffish.com out of his apartment, and raking in millions through advertising. But he’s a great example of a guy who was in the right place at the right time (not to mention a great entrepreneur).

Just because he made it work, doesn’t mean there’s an endless amount of marketspace for other free, general-interest sites.

The majority of small, niche dating sites need revenue to grow and sustain themselves. Now, if you found a few million in VC funding, you can stop reading.

For the rest of us, there’s no shame in charging for a valuable service. That doesn’t mean a general site that does the same as all the other sites out there…

But a solid niche site that solves its members’ problems well and has found a market that isn’t swamped, can and should charge for its services.

Don’t worry that charging will slow your growth: in fact, charging a reasonable fee can actually spur growth, because it lets you launch an affiliate program, which in turn can open the flood gates to new opportunities.