11% of U.K.retailers say more than half of their web sales in 2014 will occur on smartphones and tablets, according to a new survey by IMRG, a U.K. e-retail trade association. That’s a big jump from 4% last year, the survey finds. IMRG surveyed 50 retailers, including large chain merchants and large and small web-only e-retailers across a number of product categories, from fashion to consumer electronics to home & garden.

It’s not surprising that many retailers would get a majority of online sales from mobile devices considering how much consumers today rely on their smartphones and tablets. For example, 55% of all time spent with online retail in the U.S. occurs on a mobile device, finds web and mobile measurement firm comScore Inc. Smartphones account for 44% of retail Internet minutes while tablets account for 11%, comScore says.

“Mobile continues to dominate the e-retail landscape, with sales via mobile devices now accounting for a third of U.K. e-retail sales,” says Tina Spooner, chief information officer at IMRG. “The latest survey results also reveal that mobile has a key part to play in the multichannel retail environment, with three-quarters of multichannel retailers now having a mobile-optimized web site, compared with just over half of web-only merchants. With an increasing number of consumers now using their mobile devices to browse and compare products while in-store, it is no surprise that mobile has become an integral part of retailers’ multichannel strategies.”

The Goldman Sachs Group Inc., a multinational investment banking firm, predicts worldwide retail mobile commerce sales (excluding travel and excluding digital goods such as music and apps) will represent 27.2% of e-commerce sales in 2014, 33.9% in 2015, 40.5% in 2016, 43.8% in 2017, and 46.6% in 2018.

Also on the 50% mobile milestone front, 13% of U.S. marketers say more than half of their marketing budgets will be devoted to mobile by 2018, finds a Yes Lifecycle Marketing survey of 100 U.S. retailer executives.

“The emphasis on mobile, web and social demonstrates the consumer need for marketers to seamlessly integrate online and offline shopping experiences,” says Michael Fisher, president of Yes Lifecycle Marketing.

Regarding overall web sales, IMRG finds increasing optimism amongU.K.retailers about 2014 online sales. While almost all merchants surveyed say they expect to see positive year-over-year sales growth, a significant percentage (42%) forecast web sales growth to exceed 20%, IMRG says.