This is probably my favourite place in Berlin: there are lots of shops (I usually hang out at the…read morebookstore Dussman), stores (there is H&M and high-end shops), restaurants, Starbucks (super plus from me) and there are always people!
I think a lot of the stores here are targeted towards tourists or people with more-than-a-modest income. It is still a nice place to walk around, and you can also walk down the street (it is a long street) and check out the other landmarks around, all walking-distance, very appropriate for the summer. (: