The most important factor to consider when starting to build a business is the target audience. You have to think of who would you want to cater to. Who are the communities that you may profit off of.
That's target market and it's true that it's one of the most important factor in starting a business. You need to know who your customers are and that's why in an economy that's not so good, you'd see that many startups are coming up because of the needs that they need to fill when there's a market waiting for them to be spent their money on.
Like for example if there is a school near you, you should know that students would be your target audience. You should start a business where students can buy materials from or a place they can study or even hang out around. I believe that if you studied your target audience, the first step of your business is already successful enough.
So, the needs from that location and the specific customers that you're going to cater for your products. Aside from target market, the foot traffic is also what you've mentioned here and these two factors complement each other.