Publishers routinely complain that the opaque nature of the digital ad pipeline is inefficient and expensive, with middlemen taking an outsize share of ad spending. Newspaper and magazine publishers, by some estimates, collect only 30 to 40 cents of every dollar spent on their ads online, compared with about 85 cents in the pre-internet days.

“We’re trying to create new terms of trade to modernize the business,” said Joe Zawadzki, chief executive of MediaMath, an ad tech company. “Seeing where every dollar goes — that doesn’t exist today.”

The initiative is led by MediaMath, which makes automated ad-buying and data analysis tools for advertisers and ad agencies. The group’s members also include IBM Watson Advertising, White Ops, Havas Media and Business Insider.

The companies are all looking for a path to prosperity in an industry criticized for a lack of transparency, for hidden fees and for rampant ad fraud. The companies in the initiative, called Source, are trying to demonstrate that a more efficient, more open marketplace can exist.

They want to be a viable alternative to Google and Facebook, which supply tools for ad buyers and sellers and run the auctions within their digital walls. The tech giants, which are able to offer advertisers huge audiences, increasingly hold sway.