If you are doing a pitch, "Netflix for Octopusses" would make you look stupid. Grammar does matter, especially when you are trying to convince the world you aren't an idiot.
Octopuses is valid. As is octopodes, but octopi is a freak Greek-Latin hybrid by people trying to convince the world that they aren't idiots but is now also valid.
[1] http://www.youtube.com/watch?v=wFyY2mK8pxk