The whole idea of Street Pass is to promote public interest and compound the awareness for the system, covered in a gameplay mechanic. This is why you see Nintendo actually taking strides to fix it. They thought things may have picked up, but they did not.
Here's the interesting part. Now they're turning it into a slightly different kind of marketing strategy. One that incorporates other entities as well, which for Americans is a great strategy. It doesn't work like Japan here, and incorporating McDonalds and Starbucks like this is going to mutually benefit all sides. They specifically name dropped those two, which means they are in talks with them for joint marketing strategies. You may never hear anything from McDonalds or Starbucks but this name dropping guarantees they are working together for a mutual marketing strategy. Why so confident in that? Because those companies have the right to, and would gladly, sue Nintendo for using their names as promotional benefits. It falls under profiting from someone else's brand without giving royalties for it. So at this point it's pretty assured that there are multiple hands in the pot now.
A very nice strategy for all three of them really. Great way to draw in more customers on all sides.