31 Amazon rollup companies to know that specialize in snapping up third-party sellers and turning them into multimillion-dollar brands

Amazon has become a fairly efficient system for creating millionaires: In a recent Jungle Scout survey of Amazon sellers, almost 20% had made $1 million or more from their businesses on the site.

A booming spinoff economy has sprung up around taking these businesses and combining them to form uber-brands — somewhat like a Procter & Gamble.

These so-called Amazon aggregators buy the most successful brands on the site and improve their marketing, packaging, and positioning to take them to the next level of profitability. Many aggregators are also picking up companies on other e-commerce platforms, including Shopify and Etsy.

Tactics in this category are rapidly shifting, but it's now becoming common practice to take an omnichannel approach to the business: A brand may start out with a presence on only Amazon or Shopify, but the aggregator expands the brand's availability across a variety of platforms.

Many aggregators also seek out what online-shopping enthusiasts may think of as "backward compatibility," adding brick-and-mortar deals to the digital-marketplace presences that these brands have already established.

While a company such as GOJA, one of the leaders in this category, has been in business since 2009, this is such a profitable category at the moment that venture-capital money is flooding in and new companies are popping up almost every week.

Here's a look at some of the top aggregators.

GOJA

Total funding: Undisclosed

Investors: 3L Capital, Next Coast Ventures, JP Morgan

About: GOJA — a privately held company that has mostly steered clear of the rivers of venture-capital money flowing through the Amazon umbrella space (the exception being undisclosed investments from 3L Capital and Next Coast Ventures) — operates outside the spotlight of many big players.

President Walter Gonzalez said he considers the technical expertise his company offers in optimizing brands for Amazon its strong suit, while sellers that have joined forces with the group raved about the way it handled deals before, during, and after.

The company targets brands that have a limited number of stock-keeping units combining to throw off $2 million or more in annual revenue, with a sweet spot between $5 million and $15 million. The company, which has been in business since 2009, has an undisclosed number of brands under its umbrella, including Alien Sunshade, TireTek, and Love, Lori.