I'd like to look into promoting scrubbers more, whether they be buckets, acrylics, or eventually G3's. Hopefully someone else will start making them (i.e., a finished product with a name), and I can help promote them. Promotion is my day job, and we have a phone room that can call hundreds of retail stores each week. This is in addition to online promotion, of course.
I think something like a basic acrylic box, which will fit in most places, would be a best first product. Should be able to sit above most sumps, or on top of or behind tanks (must look decent, and not let light out). Pump should probably be included, in order to make things simple (a self-priming pump which can pull water up to the box).
There are two types I see as a good beginning: a small clip-on nano scrubber the size of a tv remote, that sells for (U.S.) $49 to $99 retail (incl pump), and a regular acrylic unit for up to 120g, that sells for $199 tp $299 retail (incl pump).
Marketing would of course be primarily dictated by who paid for it. But short of cash outlay, here's what I'd be able to provide:
Vendor forum support: If someone else buys the vendor forum, I'd be able to answer the questions of the customers in the forum, for no charge.
Email promotion: I'd train one of our email promoters to contact english-speaking retail and web stores (anywhere) by email, and attempt to get them to buy the scrubbers. Could be at-cost, or percentage.
Phone promotion: I'd train one of our phone promoters to contact retailers in the US and Canada, and attempt to get them to buy the scrubbers. Could be at-cost, or percentage.