While big name bricks-and-mortar retailers like Macy's (M) and Sears Holdings Corp. (SHLD) crumble, home improvement retailer Home Depot (HD) continues to have runaway success.

In large part, that's due to the ongoing recovery of the U.S. housing market and surging stock prices that are spurring people to invest in their homes. But, it's also likely because Home Depot remains relentless in trying to improve its operations to meet the ever-changing needs of consumers.

"We are constantly paranoid that we need to keep making sure we are staying with the customer and having as little friction in the [shopping] process as possible," Home Depot's President of Online & Chief Marketing Officer Kevin Hofmann told investors at a Raymond James conference Tuesday. Hofmann revealed that Home Depot completed the rollout of its buy online, deliver product from store capability to all of its 2,278 U.S. stores last year. A shopper can now buy a refrigerator on Home Depot's website and have it delivered the next day from a local store within a two-hour window. Can't get any easier than that.

Home Depot racked up $5.5 billion in sales online last year, up an impressive 19% year over year.

"We have invested in our online experience to shorten checkout times. In fact, we have dropped the time to check out by 19%. We improved the overall look and feel of the website. That matters for our category because people aren't looking at items like a cup of coffee. They are looking at a patio set or a kitchen or bathroom. So, that experience online is very important to them," Home Depot CFO Carol Tome told TheStreet in an interview.

To be sure, Home Depot is also winning in its physical stores.

The home-improvement retailer posted a monster fourth-quarter earnings beat, delivering a profit of $1.44 a share versus analysts' expectations of $1.33. Same-store sales rose a solid 5.8%, surpassing Wall Street estimates for a 3.5% increase. Home Depot's same-store sales in the U.S. gained 6.2%.

Shares of Home Depot have gained about 26% over the past two years, outperforming the Dow Jones Industrial Average's 16% gain.