Just brainstorming generally. Seeking thoughts/suggestions comparing Los Angeles vs New York City vs Austin, etc.? Any thoughts?
My answer would be none, because social media apps have been done to death. But, what it does point to is that you need to complete your research before you determine what product to launch. Let the market define what solution you're providing, and you might have a glimmer of hope for your me-too product. Ask the "five whys" and get to the bottom of why someone would actually want to do something different with social media than what they can do today. If you can fill an actual need instead of an imagined need, then you're on a path worth exploring further.
Each city in the US is going to have a different attitude, demographic profile, and likelihood of adoption. You can't say what works in NYC is going to work in Dallas automatically. When you learn what kind of people are being under-served you can match that profile to the demographics of various cities and find the level to which each is likely to support usage.
This isn't about pushing something out to a test market. This is about testing the market to see what you may be able to push.