I built a free API that translates MAC address into a vendor. The API handles a ton of traffic (pushing 300 million requests a month) but actually generates no revenue as I don't charge for it. On the homepage of the site I added a search box that lets users search for the vendor manually instead of using the API. The homepage gets enough traffic to generate some ad revenue.

I'm curious--that's a ton of requests. Any idea what your users are using the data for, and in what context?

As an example of a possible use: I know that my Asus router shows vendor info on its page that displays DHCP leases. It seems like it's mostly based on the MAC vendor ID. I haven't ever examined where it gets that information from.

From real world experience, "I see this device getting an address from DHCP but I have no idea what our where it is and there aren't any useful ports or it's off right now. Is the MAC from a manufacturer I recognize?"

~5k requests per minute doesn't seem that much if it's just light processing and a map lookup. You can do a lot with a $10/m VPS.

I'd use it to trace computers on my network.

Do you have a link to your webiste? Would be nice to see.

Side note: If you are using an ad-network then which to generate such revenue, if not how are you selling your ads?