New York adtech giant AppNexus buys digital advertising and analytics company Yieldex for $100 million

New York-based AppNexus acquired digital advertising and analytics company Yieldex for $100 million in cash and stock on Wednesday, the Wall Street Journal reports.

The two adtech companies are merging ahead of what could finally be AppNexus's long-anticipated IPO.

AppNexus raised a $110 million Series E round in September from WPP, the largest advertising holding group in the world, and has gone on an acquisition spree in the past year.

Prior to buying Yieldex, AppNexus acquired the Baltimore-based ad attribution startup MediaGlu in December 2014, as well as advertising visibility platform Aplenty in June 2014.

From the Wall Street Journal:

With the Yieldex deal, [AppNexus] is aiming to broaden its appeal to investors by adding a new frontier to the automation business: bringing more technology to the process of a salesperson selling their most valuable web ads directly to buyers.

AppNexus has a software platform that connects these bidders, and was on track by the end of last year to generate $250 million in annual revenue in 2015 and turn a profit, according to the company.

AppNexus is one of New York's hottest tech startups. Craft marketplace Etsy, another big-name New York startup, is planning its IPO this quarter.

Since its 2007 founding, AppNexus has raised more than $300 million, and has been valued at $1.2 billion.

We've reached out to AppNexus for comment and will update this story when we hear back.