Terrifying or fantastic, depending on what kind of retailer you are.
New research by by Deloitte Digital found 46 per cent of UK smartphone owners have used their device to research product info before or during a shopping trip.
It concluded that the practice influences six per cent of in-store retail sales.
Clearly, mobile research will lead to some shoppers walking out the door and going somewhere else - or buying the item from a mobile site.
But the habit can also be harnessed by more enterprising retailers to push location aware offers and communications to the same customers.
Highlighting this opportunity, the study found that 74 per cent of shoppers that visited a retailer's mobile website or app during their most recent shopping trip made a purchase, compared with 66 per cent that did not.
It's also the case that more consumers are using mobile to enable physical purchases than to buy from the phone itself.
Deloitte says the value of direct purchases made through phones will be £8 billion in 2012.
It also estimates that 15 to 18 per cent of in-store sales will be smartphone-influenced by 2016, equivalent to sales of up to £43 billion.
Colin Jeffrey, head of multichannel retail at Deloitte Digital, said: "We would expect smartphones to increasingly be used as a transactional device in the future. The increased adoption of contactless payment technology will act to accelerate the influence of mobile.
"Retailers need to plan for a world where banks of till points are no longer required and prepare to fully exploit the opportunities that mobile presents."