COLOGNE — At last year’s DMEXCO, WPP Sir Martin Sorrell promised<\/a> he would finally join Twitter – if CEO Jack Dorsey showed up at the next event.<\/p>\n Well, at this week’s 2017 occurrence of the digital ad gathering in Germany, the pair graced the stage together, and Sorrell joined<\/a> the social network live in front of an audience.<\/p>\n But that doesn’t mean the chief of the world’s largest ad agency holding group is a total convert.<\/p>\n Speaking with Beet.TV in this video interview after his appearance, Sorrell had some robust views about what advertisers need from tech companies like Twitter.<\/p>\n “We had a very strong year with (Twitter) last year,” he said. “We went up in spending with our clients from about 240 million to 300 million. (But) I think they’ve got to be a little bit less clunky on the technology front.<\/p>\n “It’s true of all the big tech companies – a lot of times the clients and the agencies say, ‘Look, can’t we have this?’, to which the answer is often a ‘No’.<\/p>\n