Speaking from past experience only, and just going off what you described, personally I would go with the first one. It sounds like they are more focused and ha

Speaking from past experience only, and just going off what you described, personally I would go with the first one. It sounds like they are more focused and have a specific plan with their business. The second choice seems to be all over the place, not sure what their business plan is, and are just throwing ideas around until one sticks. Another piece to consider is the people in general. Hopefully you have met both teams and have an idea of what they are like. Go with your gut on who you think is the better team and group you would like to work with. Finally, as it is an internship, if at all possible take the pay piece out of the equation. If you can afford to live without the pay for the period of the internship then this should be a low priority for selecting. Experience and connections can be worth more than any dollar amount down the road.