The agency follows the lead of planning and buying specialist i-level, which became the first digital-media agency this year to sign up to ABCE.
Profero, which is celebrating its fifth anniversary, will promote independent standards of electronic media to its clients, such as COI and Disney.
Wayne Arnold, chief operating officer of Profero, commented: "We have recognised that the industry as a whole is growing and developing, and we have worked with groups like the Digital Marketing Group of the IPA to discuss the issues we all face. This is another way for us to put our money where our mouth is and commit to independent standards."
Arnold added: "Our company has some pretty big clients, such as Astra-Zeneca and Singapore Airlines, which are used to having media audited in the offline world, and so we are now bringing them the opportunity to have digital media treated in the same way."
In 2002, Outrider became the first digital specialist agency to sign up as an associate subscriber of ABCE.
"This is a sign that we are in an ongoing dialogue with the key players in the industry," pointed out Richard Foan, managing director of ABC Electronic.
"There is a lot of dialogue going on about discrepancies of statistics and in some ways this helps agencies to give their clients a safety net," he added.