Exclusion Lists
⏰ Old Post
This post is over 7 years old - it might be slightly outdated and consigned to the history books.
So we've created a site wide tool called 'Exclusion Lists' -

Adding domains to exclusion list greys them out in reports, allows you to keep track of what leads you've already either added to your CRM system or excluded from your research.
Watch an end-to-end demo of how to use BuiltWith Exclusion Lists.