Surveying preference isn't a valid way of determining product viability, or even of comparing how well two products well sell.

This is not to say that you shouldn't build it. Building stuff for the sake of building stuff is a good thing.

This is also not to say that you can't make a business around product validation. There are multiple successful businesses already in the area of product validation.

I just wouldn't recommend the "Hot or Not" approach, because it's bad and generates bad data. Think who else is doing this and get an idea for what approaches there are to the problem - for example, Kickstarter.