This past holiday season nearly a quarter of online shopping was done using a mobile device – meaning it’s no longer OK for a retailer to have a good web site – they also need to master selling via smartphone.

So which retailers are winning the mobile war? We asked comScore (SCOR) co-founder Gian Fulgoni and while some of the usual suspects topped the list, there’s a few companies that might surprise you.

Number 1 on the list was Amazon (AMZN), followed by eBay (EBAY). They had 69% and 63% of their traffic via mobile devices respectively. “I think they were the two pure play online retailers who really figured out the importance of mobile first,” said Fulgoni. “They developed easy to use, powerful apps.”

As Fulgoni points out, a lot of retailers were late to understand the importance of mobile devices and therefore were slow to build easily manageable apps. Just a year ago, “I don’t think [retailers] had yet understood the importance of these mobile devices, either as a device to buy a product with, or as a device that was being used by consumers to pull in information and do price comparisons, even if the ultimate purchase ended up in the store,” he said.

Get the Latest Market Data and News with the Yahoo Finance App

When the multi-channel retailers did start to pick up on the importance of this, Walmart (WMT) and Target (TGT) were the first two to pick up on the trend; Target actually got it right first. That’s right, despite all of the publicity over Target’s hack and the criticism of their web site – they’ve actually been at the forefront of the mobile revolution, per Fulgoni. “[They] figured out the importance and came up with their own apps and as we closed out the year, both Walmart and Target’s percentage of time spent on mobile with an app was about the same as Amazon and Ebay. So, they figured it out,” he said.

Walmart was third of the comScore list of best mobile retailers, Target was fifth. In between was Apple (AAPL) – but Apple is a slightly different story because much of it’s mobile store traffic is tied to its digital downloads.

Americans these days tend to prefer the mom-and-pop retailers that big box stores once put out of business. But Fulgoni says the big guys may finally have taken back the advantage when it comes to mobile. “If you go down to the specialty retailers, they are the ones that might well have a challenge on their hands,” he said. “It's easy to forget to use the app for a retailer that you don't buy at very often.”

Specialty retailers may convince their loyal customers to download their apps, but getting them to use them is another story. Most smartphone users spend the majority of their time on a few favorite apps – favorites like Facebook (FB) dominate our app time. So that means retailers need to no only convince shoppers to use their app, but create ways to make sure they continue to engage.

And while it’s admittedly a “big challenge,” per Fulgoni, there are a number of names getting it right. Best Buy (BBY), Kohl’s (KSS), Home Depot (HD), Macy’s (M) and even Sears (SHLD) are doing something right – they round out the comScore list of top 10 mobile retailers.

Do you shop at these stores using your phone? Let us know in the comments below.

More from Yahoo Finance:
Pre-Presidential election year: No stock declines in 76 years
3 things to watch when trading this week
Oil and airline trades reverse as crude ticks higher