Loyal Engadget readers know that we don't normally trouble ourselves with promotions, but this one is too wild to ignore. Until June 30th, RadioShack is offering the HTC One to AT&T and Sprint customers with an added bonus -- a $100 credit for the Google Play store. Should you elect to sign up with Sprint, you'll basically get away like a bandit since RadioShack has slashed the price of the handset to $79.99 for new activations -- on two-year contracts, of course. After all is said and done, you would basically leave $20 richer than when you started (sort of). So,
