Hi Red,
We use the same primary filterlists as uBlock Origin, primarily EasyList and EasyPrivacy. We add some of our own filter rules to allow certain ads and content through; most notably, we allow textual search ads to be displayed from certain reputable search partners (google, yahoo, bing, duckduckgo, etc). User feedback has indicated these are the fastest, least intrusive form of ads, and the revenue from them helps support the whole ecosystem.
We don’t employ any webcrawlers today but we are always experimenting with ways to make our adblock feature better, so this is something we may consider in the future. If you have any specific ideas around this feature, feel free to reach out to us directly and share them.
Hope this helps provide some clarity!