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Microsoft wants to develop digital “money-off” coupons that can be
distributed via television sets. Instead of wasting billions on printing and
mailing special-offer tokens that most people ignore as junk mail, Microsoft
suggests companies send them electronically, hidden in TV signals (WO 01/50758).
The special offer data is hidden in the so-called horizontal overscan, the
extreme left and right edges of the picture which are not visible on screen. An
icon tells the viewer when to press a button, which makes a set-top box store
the “coupon” in a portable electronic wallet. To get your deal, you take the
wallet to the store.