... creative and media agencies to mobile and analytics firms.
It's a move that could empty the wallets of agency evaluation consultancies.
In some respects the new service is analagous with consumer-oriented Yelp Inc, a local directory service with social networking and user reviews.
According to CMO Club founder and president Peter Krainik, he often witnessed chief marketers swapping recommendations informally at the club's dinners and events. "This is us helping people behind closed doors," said Krainik of the new program.
"We're connecting people, that's what the club is all about."
Since the inception of the program at the start of 2013, between five and ten CMOs per month have added recommendations. Mr. Krainik says the listings are growing, with multiple reviews for some vendors, as well as reviews for some bigger agencies.
The group last week began the program promoting the scheme with a PR push.
Evan Greene, CMO for the Grammys, says he's a "big fan" of the vendor-rating program and has both submitted reviews and used the service for recommendations.
"It's really helpful to see what people in a similar role are doing. It's an open exchange of ideas and recommendations".
But the project begs a thorny question.
Will busy marketers - who are concerned with everything from product development to distribution channels to consumer awareness, and not just their agency relationships - have time to regularly log on to submit their recommendations?
Moreover, will they actually be willing to spill the beans? Especially as most marketers view the work done by their agencies as a competitive advantage.
Reassures Krainik: "The review process is not laborious" although it certainly is thorough.
Each entry has fifteen questions, with a mix of drop-down menus and open-ended questions, in addition to basic information like reviewer name and vendor name.
CMOs can rank vendors on quality of service, on-time delivery, price and customer service. Mr. Krainik says that reviews can't be anonymous, and notes that he has personally approved each member of the club.
Read the original unabridged AdAge article.