Mobile attribution company Kochava acquired Thalamus, a database of ad providers, and created it “like an advertiser’s Yelp” to find media, according to Charles Manning, CEO of Kochava.

Kochava hopes to turn Thalamus, renamed Kochava Media Index, into a directory of ad buyers and sellers to help marketers find new sources of legitimate inventory.

“It is very difficult to find a new range inventory. It is valuable to discover places where you can buy more media and where it is a legitimate business. That’s mainly why we made this decision, “Manning said.

Kochava does not charge a subscription to this new index. Instead, it will act as a lead generation platform and guide users to other Kochava products.

The terms of the contract were not disclosed.

“We are very excited to join Kochava,” said Garrett Gan, founder of Thalamus, in a statement. “As the largest advertising database in the industry, combining our offering with comprehensive solutions from Kochava is a powerful new offering for the ecosystem.”

Manning said all the “handful” of Thalamus employees will come to Kochava, which has around 160 employees.

Kochava recently launched a new line of products for publishers to use to maintain identity as trackers like third-party cookies and Apple IDFA are disappearing.

The Idaho-based company is one of many ad tech companies selling new products related to identity. The entire industry is building tools in growth areas like connected television, e-commerce, and data protection as the buyer side continues to move towards automation.

All of these different tools and emerging media types require a solid directory of buyers and sellers, Manning said.

“The Thalamus acquisition is central to delivering the operating system vision of marketers,” he said.