The Weather Channel is the latest media outlet to join OpenAP, the consortium of media companies working to help advertisers buy TV with some of the new methodologies they say they crave.

OpenAP was the first of several new companies formed to spur the concept known as “audience buying,” offering technologies and measurement that let advertisers move beyond the broad age-and-gender demographics traditionally used to delineate ad deals and focus more intently on buying characteristics. Advertisers can define specific audience types, such as first-time car buyers, expectant mothers or likely moviegoer, and then apply that category to purchases across various media companies.

“It’s hard to change the way you transact, but these changing times give you an opportunity to rethink things a bit,” says David Levy, CEO of OpenAP, in an interview.  Weather Channel follows AMC Networks, which announced in March it had joined the consortium.

OpenAP is growing as more advertisers clamor for new kinds of deals with media outlets. They are more interested in using brews of data that help them place their commercials in front of their most likely customers, as opposed to running ads in big-audience venues and hoping that the subsection of the crowd most interested takes an interest in the pitch. Such interests are fueled by the rise of venues that allow for programming to be chosen on demand, often in ways where consumers can interact with the media they choose.

OpenAP was formed by Viacom, Fox and Time Warner. The last left after it was purchased by AT&T, but NBCUniversal, Univision and CBS have since joined the company. AMC Networks announced in March that it had joined OpenAP.

Levy says the company has made joining easier. “We really needed to adopt a model where folks could participate in a meaningful way, join but not necessarily have to go and be a full equity member.”

OpenAP is growing as a rival operation, WarnerMedia’s Xandr, has tried to offer a similar business proposition.  AMC Networks also has an alliance with Xandr, as does Disney Advertising Sales.