Shoppers bought more than ever during this year’s blockbuster Black Friday and Cyber Monday.

But where they shopped should be a warning to retailers. The data suggests that it's imperative to make sure mobile apps and websites are ready for a future that will be ever more focused on Internet transactions.

According to data from National Retail Federation’s Thanksgiving Weekend Survey, more than 151 million people said they shopped in stores or online, a leap over the 136 million who planned to do so when asked about it in mid-November.

Nearly 103 million shopped online, a slight edge over the 102 million who said they only went to the stores.

Shopping and More Shopping

The slight edge for online shopping is significant, as it indicates that more than ever shoppers are choosing to attack those holiday deals on their smartphone or computer instead of charging through the mall.

As evidence, consider the findings from Tel Aviv-headquartered SimilarWeb, which reported that US retailers that closed their stores on Thanksgiving and Black Friday outperformed competitors online.

According to numbers from Adobe, $11 billion came from online sales alone, a 15 percent increase from the previous year.

Online offers another advantage, according to Adobe research.

Buyers tend to hit physical stores to grab the doorbusters and leave. With online shopping, they’re more apt to browse around at other merchandise and pick up a few other things before hitting the “submit” button.

Cyber Monday? Meh

Yet the ubiquity of shopping opportunities might eventually make such online extravaganzas as Cyber Monday irrelevant.

Amazon, for example, already is calling its special sales “Cyber Monday Deals Week.” Motorola’s online store is running many of its online specials through Dec. 7. And retailers like B&H Photo are continuing to offer daily specials exclusively inside their mobile apps.

Also, many of the big deals at major outlets like Best Buy were available on their web site as well as in person.

With so many high-profile incidents taking place at stores (think about those videos of fights and your experience stuck in crowds), it might be easier to stay at home and shop from your smartphone.

A Big Win for the iPhone

When it came to mobile shopping, the iPhone was clearly the device of choice. According to a report by Branding Brand, nearly 80 percent of purchases came from one of Apple’s mobile devices.

This was especially the case for those in the 18 to 34 bracket, who were more likely to favor smartphones than any other age group.

An Interactive Advertising Bureau (IAB) report also found more than half of shoppers still “showroom,” which means go into a physical store to handle or check out the merchandise before going online to make a purchase.

It may not be long before we specific days like Black Friday and Cyber Monday mean even less.

The weekend may just kickstart the shopping in total, with retailers on- and off-line throwing out a stream of deals to try and lure in shoppers to their sites and apps.

This gives a big advantage to companies with a large Internet presence who can vie for attention. The challenge will be for small businesses that still rely on foot traffic to get noticed during the major rush.