Have you ever tried partnering with OpenDNS to add your Categories on specific topics to their broader categories? When my son was young I used a combination of tools to block as much as possible as well as a mobile phone app to block a lot and it would have been nice to have your website during that time. I use OpenDNS both for filtering and for speed which is key because if look-ups are slow it affects usage.
OpenDNS has a decent list of Categories but mostly broad in nature but you can suggest other Categories (whether they accept it is another issue) as well as block individual websites and domains for those who are capable of managing their own. Yours would certainly be on par with their filtering but maybe you have some secret sauce they could incorporate into their platform plus you could make some money for your causes.
Just a thought. I do mention your site to folks with little kids when the opportunity arises. God Bless your work and I have added you to my daily intentions in the hopes more people opt in.
