This may just be me but i dont think thre needs to be 1 Icons/Buttons for the shop on the Battle.net a single Shop button should work just fine. If wanted to let the players now theres a ‘sale’ on stuff for a particular game. whenever theres a sale put the Sale ‘button’ where the shop icon is on the screen that way they can see if theres anything they want.
With games Like Diablo, Starcraft and even the Warcaft RTS games they got 2+ games for them. Maybe have all Diablo Listed under 1 icon, have both Starcraft Listed under i Icon and all the Warcraft RTS listed under 1, and on the same Line that has Patch Notes and Forums have a selecteable otions of how many games are in that series this way the battle.net doesnt get bloated with so many game options to have on the Battle.net. So for Example with Diablo it would nhave 1, 2, 3 and 4; for Star Craft it just be 1 and 2 and so forth.