I have come to notice that many of my millennial friends are not avid mobile shoppers, as many would assume.  HOWEVER, what they will buy via mobile are DEALS!  “Almost half (44%) selected a coupon or deal for a product they are looking for and 37% said they would want a close by sale or coupon.”

By offering deals, you increase your traffic.  Your cost of advertising is covered by the discount of the item and you attract new customers.

65% of Millennials Don't Purchase by Mobile

Chuck Martin

For all the emphasis on appealing to millennials, the group doesn't seem to have bought into the idea of mobile purchasing. And of those who do buy via mobile, there's hardly a consensus on the attraction of apps vs. mobile websites. The majority (65%) of millennials do not buy anything monthly from their mobile phones, according to a survey by Social Lens Research.