He will join trading team leaders Danny Lloyd and Paul Mann who have also been named managing partners, as part of a management restructure focusing on Miroma’s expansion in the UK.
Poole, who joins Miroma in November, left ITV-owned GMTV earlier this year. Prior to joining GMTV, Poole was associate director at CIA media.
In addition to Duff, the triumvirate will "spearhead the company’s strategic aim of establishing corporate barter as an integral part of the marketing mix, delivering consistent value for advertisers, media owners and agency partners", according to Miroma.
Duff said: "Our phenomenal growth shows no sign of abating and I am determined that we continue to accelerate our ability to deliver to all our existing and potential advertiser, agency and media owner customers.
"Simon's strong track record in delivering pro-active, innovative and collaborative business solutions will further enhance the great strides made to date by all the team at Miroma. I'm delighted to be able to recognise Danny and Paul's contributions to our progress with their well-deserved promotions."
Poole added: "I am delighted to be joining a truly innovative company and am looking forward immensely to the challenge of helping drive Miroma's continued growth."
In June, Duff, the former EMEA president for Interpublic's Mediabrands division joined Miroma following 18 months' sabbatical.