Pick a company that's doing well and you can probably name two to 20 different products or divisions that it is responsible for creating. That's because, as a business grows in revenue and stability, there is always the temptation to expand into new product markets.

However, some brands have done well to stick to what they do best, leaving the desire to bring on new product lines to the other guys. These six companies take repetition to a whole new level, offering reliabili💫ty and quality via a single product concept.

1. Crocs

These kinda-ugly, but ♚super-comfy, foam resin clogs have been a huge hit since they were first released to the public.

An estimated 150 million Crocs shoes are sold every year and the footwear giant shows no signs of stopping. With ಌa wide variation of the basic clog from which to choose (toddlers, women, men, athletic, dress, and beach-inspired, to name a few), the sky really is the limit for this business.

2. Spanx

In the🐭 never-ending battle of the bulge, women have relied heavily on high-quality underclothes to help make them look their best.

The idea for Spanx was born the day Sara Blakely cut the feet off a pair of pantyhose and wore them under trousers to a party. She felt and looked great. Spanx is no doubt one of the m𝔍ost respected names in this niche, offering just the bare essentials to women (and men) around the world.

While the company has gotten smart in the offering of bras, panties, maternity, and men's solutions, its sole concept and purpose is still the same: what goes on under your clothing is entirely Spanx's business.

3. Michelin

In a day and age where most companies have almost too much going on, Michelin has remained faithful to the cause of str♑ictly manufacturing qual🎃ity tires.

Planes, cars, bikes, and more have benefited from over 130 years of tire-making success, giving the creator of the first radial tire a customer base that spans the globe.

While this company has dabbled in the fine art of creating rocket fuel components and designing road maps🌞, the famous tire division is what keeps this company moving forward.

4. Roku

Roku offers an innovative solution for our desire to connect to a world of content at the click of a TV remote. Its Roku player is a small electronic device that, when linked to your television and an internet connection, offers access to Amazon Prime, Netflix, Hulu, Apple TV+, the major networks, and so much more entertainment.

There's a strong possibility that it may create new and different product lines, as Roku has expanded to include more high-tech versions of its original Roku player.

But the single concept of connecting TV viewers to online content remains intact. The company knows what it's doing. Adding more features to its primary product line is what keeps Roku customers happy.

5. Gorilla Glue

If it's broken, why not fix it? Gorilla Glue is a handyman's dream, offering a strong bond for almost any surface and a drying time that gives it a top spot in the tool kit.

To keep it at the top of its market, Gorilla's DIY guides give customers inspiration for creating the projects of their dreams—with the help of Gorilla Glue, of course.

While Gorilla's family-owned company does get into the tape and epoxy game, its famous glue is what keeps it in business.

6. Sleep Number

The commercials speak for themselves: Sleep Number is all about a good night's sleep, and this company hasn't attempted to do anything but beds and pillows in their over 20 years of business.

Best-known for the adjustable Sleep Number mattress, the company rebranded from Select Comfort to the Sleep Number Corporation in 2017.

Sleep Number has been ranked consistently as a top option for bedding and offers its wares in-store, online, and via its convincing infomercials. Even with an expanding accessory line that includes more pillows and sheets, it's the bed that gives this company its thunder.

The Bottom Line

Some companies start with a single product concept, and mix in excellent marketing, s𝓰ales ef🌺forts, and business smarts to propel their business forward. That concept, though it may result in variations of the primary product over time, allows them to grow and prosper without branching into other products or services.