The first business that I started was a free employment paper. I talked to potential readers and got their feedback pertaining to my product as well as an understanding of how they searched (at the time) newspapers for jobs. This research confirmed that our paper would have readers and therefore likely be successful in generating results for advertisers.
I then called advertisers and pitched them on buying an ad—I even managed to close a few sales on the phone. This was a very good result considering I was calling them from my small, very hot apartment wearing gym shorts and that I had neither a real product nor a company. As well, it clearly confirmed to me the price points that would work. Asking someone for money is a great way to see if your idea is of interest. General questions like “how do you like this idea etc” get polite, general answers but there is no better research into sales than to ask to be paid. You will either get a Yes or a No—and a reason why.