Optimizing Your Join Avenue - BW2

The Join Avenue, located just south of Nimbasa City, is a new addition to BW2 that allows you to set up a maximum of 8 shops, and there are 8 different types of shops to choose from.  So, should you have one of each shop?  Are there shops you should have more than one of?  Are there shops that aren't that useful?

The goal of this post is to give you an idea of what shops to open, depending on your playing style.

Watch Out for the Diamond Dust in BW2

For those of you who didn't know, diamond dust is a rare weather effect that was introduced in Diamond and Pearl, and has been in every core title since then.  Here's how diamond dust looks like:

Diamond dust in Snowpoint City (Platinum) - image from Bulbapedia