Small businesses might want to ramp up their app efforts.

A new study from Deloitte, a corporate finance service, revealed that smartphone and web services will eventually account for $628 million to $782 million (17%-21%) of in-store retail sales in the U.S. by 2016.

“[Mobile] is rising to the top of many retailers’ agendas,” Ian Geddes, Deloitte’s head of retail, said in a press statement. “Its influence is only going to increase, so it is very important for retailers to get this right.”

According to the research, mobile and web services gave retailers a 5% boost in in-store retail sales ($159 billion).

The study also included research out of the U.K., which could have broad implications for the U.S. market.

In the U.K., at least 46% of smartphone users research a retailer’s products on their website before setting a foot in the physical store. A whopping 74% of shoppers who visit retail’s mobile site or app will purchase a product.

To no surprise, mobile retail services affected electronics outlets the most. As TechCrunch pointed out, the study showed that mobile services affected 10% of the United Kingdom’s in-store electronic sales, while convenience stores only saw an influence of 2.9%.

Still, might want to boost those numbers up. As mobile payment start-up Square just secured another $200 million in funding, it does look like the walls between in-store purchases and web shopping are constantly thinning.