The only source for this item is a promotional page on WIRED, not a business news report. It describes a straightforward offer: Western Digital will take 15% off a customer's first order when that customer registers an email address. No other terms, conditions, or business context are provided.
Because there is just one source and it is a promotional listing, there is no independent reporting to compare or contrast. The significance, if any, is that Western Digital is using a direct-to-consumer email capture tactic to encourage first purchases. Beyond what the promo code states, no further claims can be made.