Cool idea, but...

1. It's very slow (HN effect?), speed it up 2. Domain Name isn't great 3. I can't jump to a letter via hyperlink 4. I see something called Regex search...what is that? 5. I'd like to see 100 or 500 names per page since there are 256,000+ pages

Honestly, you'll likely never make too much money off ads since the demographic of your audience is technical enough that they probably have an ad blocker installed or they have trained themselves not to click on ads.

Instead of clicking to the whois information, link to some registrar that has an affiliate program.