Yotpo has closed $51 million in funding for its platform to help businesses improve their user engagement through fan contributions, such as user-generated videos. The startup has raised a fourth round of funding to finance its marketing platform that makes it easy for companies to enable such content.

Israel-based Yotpo said that the whole point is to let customers do your advertising for you. It’s more authentic, doesn’t cost as much as traditional agency-produced advertising, and increases the engagement that the most-loyal fans have for a brand.

It’s also important because the advertising landscape has changed. Traditional media outlets don’t have a monopoly anymore, and user-generated content has become huge on consumer platforms such as YouTube. Yotpo enables customers to collect content — like reviews, photos, and Q&As — and then use it to build a better customer experience and brand.

Above: Yotpo enables consumers to create promotional content for brands.

Image Credit: Yotpo

Yotpo’s newest investors include Access Industries, which led the round. The investment brings the total funding raised to $101 million. The company says it has quadrupled revenues over the past 20 months, though it didn’t provide any numbers.

Yotpo will use the money to meet demand from high-growth commerce brands for an integrated user-generated content platform. It will also invest in research on tech in such fields as artificial intelligence and machine learning.

While others focus on solutions for reviews or photos, Yotpo’s platform lets brands collect, curate, manage, and respond to all types of user-generated content. The goal is to increase trust for the brand, bolster social proof, and ultimately boost sales.

“We’re living in a post-Amazon world where even big, established brands are collapsing because it’s impossible to compete with Amazon on price or fulfillment,” said Yotpo CEO Tomer Tagrin, in a statement. “The only way commerce brands can win is through customer experience and building an authentic brand that people truly care about and talk about.”

Above: Yotpo’s platform lets consumers create authentic advertising.

Image Credit: Yotpo

Yotpo helps users create videos, reviews, and photos, and drive interest in a company’s website and products. It also has tools to help drive search engine optimization. Thousands of brands are using the platform, including TYR, Staples, Everlast, MVMT Watches, UnTuckit, and Brooklinen.

Once a business enrolls with Yotpo, the company uses data to identify optimal methods for convincing a user to generate his or her own original content across various media platforms. That means Yotpo already “knows” (and keeps learning) how to engage specific customers post-purchase (when to do email targeting, when to request a review) to have the best chance of getting them to write a review or share a photo or video.

The company had 160 employees in June 2016, but it now has 270 employees in Tel Aviv, Salt Lake City, London, and New York.

Other investors include Bessemer Venture Partners, Marker LLC, Vintage Partners, Blumberg Capital, Rhodium, and 2B Angels. Vertex Ventures joined the round as a new investor. Daniel Shinar, ClalTech CEO and Access Industries’ head of Israeli tech investments, will join Yotpo’s board.

Sign up for Funding Daily: Get the latest news in your inbox every weekday.