They provide information you can use to make a purchase decision about a tech product.

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For the past three product upgrades, iPhone unit sales have jumped 41%, 66% and 117% as consumers wait to see what is coming out to make a purchase decision.

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The smartphone becomes the tool by which retailers can directly engage and influence purchase decisions while the customer is in the store and just before they make a purchase decision.

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Take, for example, a 2012 study from the Interactive Advertising Bureau, in which 76% of consumers said they used their mobile phones in-store to help make a purchase decision, and more than half (53%) abandoned an in-store purchase because of information they found, such as lower prices or a negative review.

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It is one thing to argue that American smokers make a conscious decision to purchase cigarettes despite warning labels and that, accordingly, the tobacco companies are not responsible for their loss of health.

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Not everyone has the courage to make a quick decision about a purchase at an auction, Hu says.

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