Also this seems quite expensive. I also built such a site. There you can target nostr accounts by keyword.

1. You select nostr accounts by keyword search in their bio or in their post.

2. Zap them.

But I realized how fragile this is, and makes less sense from advertizing perspective as you cannot know if paid amount really worthed it or not.

So I came up with the #zapvertizing 2.0 model, that I am building now.