Upselling is a sales technique where the salesperson encourages a more expensive purchase by a customer by persuading them to get an upgraded version of an item or to purchase add-ons. Remember our food processor example? That food processor could probably be best used with a book of recipes, which also can be purchased at the same company’s website.
According to a paper by Duncan Watts and colleagues entitled: "Everyone's an influencer", the most common risk in viral marketing is that of the influencer not passing on the message, which can lead to the failure of the viral marketing campaign. A second risk is that the influencer modifies the content of the message. A third risk is that influencers pass on the wrong message. This can result from a misunderstanding or as a deliberate move.