I don't know that I can exactly confirm that, but here's a phenomenon I've seen literally half a dozen times in the area where I live (Vancouver, B.C.) ... a Starbucks opens up in a shopping or business-commercial area and is successful. Soon another coffee shop opens up very close by, and within a short time both places are usually packed.
Yup, ever notice that one bank, is surrounded by every other bank, usually within a few blocks. The branches seem to just pop up, all around each other.
This is also like bathrooms. There are either tons of them, or you do that buckled hopping thingy. Same goes for pencils and pens, or my coffee cup, or change for that matter. There is a scientific reason for all this, just waiting for a chalkboard...