Radio Shack made next to nothing on the per-unit sales of the iPhone. Unless BB is getting a deal from Apple, they probably do not make much profit on each iwatch. IOW, increase in sales, but not necessarily profits.
That really makes sense. . . they make no money on the great sales of the Apple Watch in 300 stores so they are going expend lots of money accelerating their time table to add it to 750 more as quickly as possible, getting it done by September instead of December, so they can make no money on the Apple Watch in those stores too! Do you realize how insane you sound? Businesses such as BestBuy are in business to MAKE money for themselves and their investors, not for someone else.
By the way, there is no such product as an "iWatch." The TradeMark for iWatch belongs to another company. Apple is even being sued by the Trademark owner for Trademark infringement even though they don't even use the name in their advertising, or even mention it, and never have. . . only the Apple haters call it that. Hilarious.
With the iPhone, there are a lot of ancillary sales: Cases, screen protectors, chargers, speaker docks, and so on. I don't know what kind of accessories they can sell with the watch.