Creativebrief is a global interactive site that enables agencies to showcase their work, staff and credentials to prospective clients. These clients can then use the site's interrogation tool to quiz agencies, without revealing their identity.
The company is the brainchild of Holmes, a former Grey vice-president and Lowe and Saatchi & Saatchi director, who has been researching the project for the past three years.
Holmes will be joined by Howard-Spink, who will be a non-executive chairman, and Jones, who will form part of the Creativebrief's advisory team.
Client-side expertise will be provided by the sales and marketing director, Paul Duncanson, who has more than 20 years' marketing experience with Coca-Cola, Glenfiddich, Scott-Andrex and Sony.
The participating agencies will be charged £140 for one year's membership.
Duncanson was keen to play down comparisons with the AAR. He said: "We do something quite different to them. We don't offer a subjective consultancy in the way they do. What we offer is the first objective, international business tool for the advertising community.
"We're more than an e-commerce site or an advertising directory. Our offering is wider as we also showcase the details of actors, actresses and production houses."