An Israeli start-up that provides technology for the development of browser extensions has been sold for $37 million. Israel’s Crossrider has been bought by e-commerce company Market.com, which will continue to operate the developer as before, the company’s CEO told reporters.

Crossrider’s is an exceptional success story. It’s less than two years old, and already has over 200 million users of Crossrider-developed extensions for browsers. With the “browser wars” heating up to full steam, Crossfire’s easy-to-use platform that allows users to develop cross-browser extensions has made the company a sort of “kingmaker.”

Extensions — the small scripts and applications that extend the use of browsers — have turned into an important way for browsers to add usability, making Crossrider, with its platform to develop extensions that look and feel the same across browsers, an extremely important resource for companies that increase user interaction through extensions.

When an extension is used the same way on the major browsers — Google Chrome, Mozilla Firefox, and Microsoft Internet Explorer –users are more likely to stick with them, thus increasing the bottom line for companies that develop extensions. One example is a shopping extension that lets users check prices on shopping sites and compare them to the price on Amazon.com. When a user clicks on a link generated by the extension and buys something, the extension developer gets a cut of the sale. Developers using the platform have other tools that are making them money as well, and with Crossrider, developers can ensure that they continue to do so no matter what browser users prefer.

Browsers have become a big business — not in and of themselves, but for the search engines they use. Searches are worth money to browser makers, following the “Google model,” in which Google makes money each time a user clicks on a sponsored links. Microsoft and Mozilla, realizing the money-making potential, have joined suit. The browser is the key to getting the clicks on those sponsored links. Crossrider has tapped into a very important niche with its extension platform, which makes it worth $37 million to Market.com.