The vast majority of grocery shopping still happens in stores, but access to web and mobile technology is having an effect on how consumers make decisions at their local supermarkets, a pair of recently released studies conclude.

One of the surveys, conducted by Deloitte Consulting LLP, finds that 51% of grocery sales in 2016 were influenced by digital activity prior to purchase, up from 33% in 2015 and 22% in 2014—putting digital influence at the supermarket at the same level as health-related purchases and not far behind apparel sales, 56% of which are influenced by digital.

The use of digital resources by grocery consumers takes a variety of forms, Deloitte says. For example, 80% of shoppers surveyed use a digital device to browse or research grocery products and 77% use “digital touch points”—retailer websites, blogs, YouTube videos, recipe websites, social media, etc.—to become more familiar with grocery brands and products. In addition, 41% of respondents use grocery retailers’ apps, 34% use a smartphone to help choose brands during a shopping trip and 29% say they try products based on online recommendations or reviews.

All of the digital activity appears to be mainly good news for retailers. Deloitte says consumers who seek information on the web before or during a shopping trip end up buying 9% more frequently than those who do not. And 19% of the time consumers’ use of digital resources increases grocery spending. However, only 31% of grocery shoppers said digital resources make grocery shopping easier, compared with 42% across other retail categories.

“Digital is expected to play an even bigger role in delivering the experiences shoppers desire,” says Rich Nanda, principal, Deloitte’s U.S. consumer products corporate strategy and growth leader. “However, many consumer products companies and their retail partners have yet to take full advantage of the opportunity, potentially leaving money on the table.”

While some may be discouraged that less than one-third of online shoppers believe digital makes grocery shopping easier, Nanda sees an opportunity.

“Part of this is a learning curve,” he says. “Grocery just hit the tipping point for digital influence.” Grocers are experimenting with ways to reach digital shoppers, he says, so it will take time to find the formula that works best for their customers.

Nanda says he does not like to predict the future, but he thinks it’s safe to say grocery stores are not going away anytime soon. That means omnichannel options like buy online, pickup in store will continue to enable grocers to offer a growing list of consumer options.

“I think click and collect is absolutely going to be part of the equation because stores are going to be part of the equation,” Nanda says. But, in a lot of cases,  delivery to homes makes sense for consumers too. As in the physical world, he says, consumers are likely to embrace a variety of retailers, including specialty retailers, to meet specific needs.

Voice shopping will become a more important part of online grocery shopping, if only because devices like Amazon Echo and Google Home make it so easy to verbally add items to shopping lists, he says.

In a separate survey, PowerReviews, a consumer feedback technology company, finds that only 17% of those asked said they purchased groceries online in the last 90 days and, among them, 92% reported also buying grocery items at a store during the same time frame. However, consumers carry their smartphones with them all the time and, according to PowerReviews, they are using them in grocery stores.

PowerReviews finds that 59% of grocery shoppers use smartphones to help them make purchases. That includes 32% who use their phones to find or redeem coupons and 30% who review digital shopping lists.

As with other kinds of online shopping, online reviews are important to consumers who buy groceries online, PowerReviews says. The survey finds that when product reviews are available on an online grocery service’s website, 93% of shoppers will read them at least occasionally, while 19% of online grocery shoppers always read reviews for grocery items, and 34% say they read them regularly. When considering grocery products they have never purchased before 72% of online shoppers are more likely to buy an item if customer reviews are available.

Making product reviews easy to find is essential, PowerReviews says. 53% of online shoppers prefer to find this content directly on the website or app they’re using to purchase their groceries, while 38% want to find grocery product ratings and reviews on Amazon.com, and 9% prefer to find reviews on third-party review sites.

The PowerReviews survey also asked what kinds of retailers consumers use to buy groceries online and what they buy. The survey finds that 39% use online-only delivery services such as such as Peapod LLC, No. 62 in the Internet Retailer 2017 Top 500), and AmazonFresh, while nearly the same percentage (38%) go online to order directly from a local grocery store for pickup or delivery. Meal-kit retailers, such as such as HelloFresh and Blue Apron (No. 197), are used by 34% of online food shoppers, while third-party delivery services, such as Instacart and Shipt, are used by 17%.

PowerReviews says shelf-stable items are among the most popular grocery items purchased online: 58% of online grocery shoppers said they purchase non-perishable packaged foods on the web; 49% buy personal care items, such as soap and shampoo; and 45% shop online for home care items such as detergent and cleaning products. However, 47% of online food shoppers go online for fresh, perishable food. Other popular grocery items shoppers are purchasing online include frozen foods (32%), soft drinks (33%) and alcoholic beverages (12%), PowerReviews says.

Whether consumers shop for food online is partly a function of where they live.

PowerReviews finds that 23% of consumers live in a city with a population of 500,000 or more have made an online grocery purchase in the last 90 days, compared to only 10% of consumers who reside in towns with a population of less than 50,000, which are less likely to offer a variety of online options for buying food. For example, AmazonFresh, the arm of Amazon.com Inc. (No. 1) that provides same-day or next-day delivery of groceries ordered online, is available only in only a dozen metropolitan areas nationwide.