Now I'm thinking it could be a subscription service - so you could choose a couple of filters (like low performance) and a city, and you'd get, say 5-10 unique to you & vetted leads every week

I think you could maybe tier it if you wanted to maximize your profit opportunity. Random numbers here but: $10/month 5 leads, $15/month for 10, $20 for 15, whatever.

Having just a flat value proposition won't make you as much, people seem to love the tier system as it gives more control to them and lets them get the number of leads that they need to satisfy their business goals.

In addition to the number of leads being tiered, perhaps you could also include in your tier packages the number of filters. This would especially make sense in the case of agencies that offer various services. If they are a web dev agency, they might want to target multiple different client types.

You should offer people the flexibility to choose the plan they want so you can maximize the revenue off of the site. You might have to play around with the options to find what the best offerings for each tier are, but I think that would be a much better way to structure it.

Thoughts?