It’s no real secret that online shopping has been siphoning business away from brick-and-mortar stores for a while, largely driven by sites such as eBay (EBAY) and Amazon (AMZN).

It wasn’t until Black Friday 2013 and the following Cyber Monday, however, that the scope of this migration became a real worry for old-school, non-digital retailing. On the other hand, it’s wonderful news for owners of AMZN or EBAY stock.

But are AMZN stock and EBAY stock good bets to take advantage of this year’s Christmas gift-giving though? And if so, which is better?

AMZN, EBAY Stock Better Bet Than Brick-and-Mortar

The most recent bad news for those who have bet on brick-and-mortar companies instead of EBAY stock? Black Friday 2013 foot traffic and sales were a disappointment to say the least. ShopperTrak reports that Black Friday in-store spending fell 13.2% this year compared to last year, in line with the 11.4% dip in foot traffic.

Granted, the big dip may have been exaggerated by the fact that more retailers opted to open on Thursday of this year. But even Thursday’s sales weren’t strong enough to fully offset Friday’s revenue dip. All told, the National Retail Federation says total spending — online as well as offline — over the course of the four-day Thanksgiving weekend fell 2.9% compared to last year.

While overall spending may have been alarmingly weak this past weekend, it wasn’t a bad weekend at all for shopping sites like Amazon and eBay — which had EBAY stock holders smiling. ComScore says online purchases were up 19.7% on Thanksgiving day itself, and e-commerce revenue was 18.9%stronger on Black Friday 2013 compared to the year-ago figures.

According to IBM’s numbers, that sales growth stayed strong all the way through Cyber Monday 2013 when online purchases rolled in 21% higher than last year’s Cyber Monday’s total online spending. eBay and Amazon led the Cyber Monday charge: AMZN Cyber Monday sales were up more than 44% by early Monday evening, and EBAY sales were up a little more than 32% at the time ChannelAdvisor tallied the numbers.

While at first glance the decline in in-store spending seems to be offset by the uptick in online-shopping, it should be noted that companies like AMZN and EBAY aren’t stealing brick-and-mortar stores’ business on a dollar-for-dollar basis.

In-store shopping still accounts for about 86% of all spending this time of year, with e-commerce only making up about 14% of annual holiday-driven retail consumption. So it’s important for AMZN and EBAY stock holders to realize that its much easier for those names to produce a larger growth number — in percentage terms — within the online-spending realm.

Then again, for stakeholders in EBAY stock or AMZN stock, the dynamics of the online/offline relationship are irrelevant. E-commerce plays are seeing a ton of growth for themselves, and that’s all that really matters to those online-retailing investors.

What if, however, there’s only room for one of the two dominant online-shopping names in your portfolio? Should you snag EBAY stock or AMZN stock?

EBAY Stock vs. AMZN Stock

Though Amazon technically posted stronger Cyber Monday sales growth than eBay did, one good day does not make a particular stock more investment-worthy than another. In other words, what’s going to drive AMZN or EBAY stock higher for the long haul is reliable, sustainable, and profitable progress for the foreseeable future.

From that perspective, EBAY stock is the (much) stronger buy here, even if the investment was only prompted by a fantastic start to the holiday shopping season.

While AMZN continues to dominate the e-commerce landscape in terms of size, the habitual big-spending and thin-margin-producing company has weakened its margins to the point of being almost non-existent; net margins have totaled 0.2% for the past twelve months. Though the pros and the company itself currently predict wider margins in 2014, they didn’t exactly anticipate 2013’s heavy spending and anemic profits in the pipeline.

Meanwhile, owners of EBAY stock enjoyed more typical profit margins of around 17.7% for years now, and they’ve enjoyed reliable revenue and profits for years. The ongoing migration from offline to online consumption — even above and beyond the period from Thanksgiving through Cyber Monday — is only apt to enhance the already-solid results from eBay.

All in all, EBAY stock is a great bet this holiday season.

As of this writing, James Brumley did not hold a position in any of the aforementioned securities.