Shopping is moving online, and the trend kicked into high gear this holiday season.

Online spending jumped around 16%, according to comScore, much faster than the 4% rise that's expected for total holiday spending. That's great news for major online sellers like Amazon.com (NASDAQ:AMZN) and eBay (NASDAQ:EBAY), which analysts expect to book revenue growth of 26% and 18% in the fourth quarter, respectively

But a few physical retailers are joining in the fun, too. Here's a look at two retailers that managed to report surprisingly strong online sales growth for December.

Company

Online Sales Growth

Macy's (NYSE:M)

51.7%

Kohl's (NYSE:KSS)

46%

Source: Financial filings.

Macy's huge jump in online revenue helped the company book a 4.1% rise in comparable sales in December. That was a bit less than the company expected, but it still constitutes solid growth in a hyper-competitive month. Critically, Macy's only had to walk back its fourth-quarter profit forecast a tad, to around $1.93 a share instead of the $1.96 it was expecting before. Discounting didn't take a huge bite out of the company's profits this season.

Kohl's can't say the same about its own results. The company only managed a 3.4% bump in sales for the month, and that was after slapping major discounts on slow-moving inventory. Kohl's took a hatchet to its fourth-quarter profit forecast as a result of the price cuts. It's now looking for about $1.61 a share in earnings, down from the $2.04 Kohl's originally expected. The retailer's near 50% boost in e-commerce sales seems to be the one bright spot in an otherwise rough December.

While both retailers came in on the low end of sales guidance, they each managed healthy online growth in a tough retail environment. Sure, it is physical selling that makes the bulk of their profits. But the online channel is an important source for future growth. And it is anything but a sure bet for sales gains these days. Just ask J.C. Penney (NYSE:JCP), which booked a 37 % dive in e-commerce sales last quarter. Unlike that struggling retailer, Macy's and Kohl's have some decent online momentum to build on in 2013.

Fool contributor Demitrios Kalogeropoulos has no positions in the stocks mentioned above. The Motley Fool owns shares of Amazon.com. Motley Fool newsletter services recommend Amazon.com and eBay. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.