Is the market size worth it? How will you reach the every-day regular-John-Smith families who aren't going to be keeping an eye out for a service like this?
I think there's definitely a market for it. Before people go out and buy fish, they usually do some research first on what it will entail, so if this site can also become a really good source of fishkeeping info and shows up on page 1 when people search for something like 'fishkeeping' or 'fish tanks' then that could be good
I guess I'm not totally aware of who the "they" are in "they usually do some research first" because I feel like a significant chunk of fish purchases come from parents of little children who are already sleep deprived and go to the nearest pet store or (God forbid,) Walmart or any other shop where they know there are fish.
If you're correct that "they usually" actually do research beforehand, there would probably be a market big enough to sustain a small online business.
