SMG launched NextTECHnow, an initiative to build the UK agency's links with start-ups in London's Tech City cluster and introduce them to clients, a year ago.
Jim Kite, who heads NextTECHnow, said: "A lot of media agencies say they are working with start-ups but you tell me how many start-ups say an agency is helping them generate revenue?"
The 22 partnerships have generated about £250,000 in revenues for the start-ups, which Kite admitted sounded "relatively low".
Clients spent on average about £6,000 when they commissioned work from a start-up at the start of the NextTECHnow initiative but that has risen to an average of about £12,000 per project. The sums vary from £2,000 to £20,000.
He said: "I don’t think many agencies would say they have generated £250,000 in revenue for start-ups in a year."
SMG has gone on to launch NextTECHnow in Russia and Turkey.
Kite said: "We introduce the start-ups to clients, we help them with their sales pitch, we help them if they need to change their technology. We want the start-ups to grow."
He added that SMG never pushes for a start-up to work on a piece of business "unless it's been activated by a client" which wants the partnership to happen.
Kite claimed other media agencies will often make contact with a start-up "to win business" from clients "and then don't pursue it" with the start-up afterwards. He added: "Start-ups are often only five or six people. If they do a lot of work and it doesn't go anywhere, it creates a lot of resentment."
He said NextTECHnow was good for SMG even if the agency does not get an immediate financial benefit. "If we can help start-ups, it makes our clients happy, and it eventually drips down to us."
SMG has invited 120 ad and tech-focused start-ups to visit its London offices to meet account teams and clients since the start of 2015.
Elizabeth Hodson, the media manager at Heineken UK, said: "NextTECHnow has been one of the driving forces behind Heineken's innovation and test and learn agenda.
"To see such diverse, motivated and young talent has been eye-opening and truly inspirational to our brand marketing teams. Indeed, two start-ups that we have got to know through this unit have now been activated on Heineken brands."
Rowly Bourne, the founder of ad tech start-up Rezonence, said: "Starcom Mediavest Group is definitely seen to be the agency that has an ‘open door’ policy with the start-up community."
Iain Jacob, the EMEA president for Starcom Mediavest Group, added: "At SMG we have pioneered this new way of working with impressive results for our clients’ brands and the tech community."
He said NextTECHnow fitted in with parent company Publicis Groupe’s new Publicis 90 initiative to invest its own money in 90 start-ups to mark its 90th anniversary.