The news, which follows closely on the heels of , comes as the company prepares to roll out its proposition and product portfolio to the European search market.
Tucker, who has over eight years' experience in online marketing, was previously at digital marketing firm TradeDoubler, where he was also sales director.
Marin was previously a senior director at Publicis Groupe's Performics, where he provided European clients with paid and natural search marketing services.
At Marin, he will be responsible for building the client services team to help strategic and advertising clients use Marin Software's proprietary paid search marketing technology.
Stevenson said: "Both Brian and Matt have the perfect background to keep Marin Software at the forefront of search marketing.
"Through their years working within the digital marketing arena, they have both built valuable experience of the online advertising world and fully understand the requirements of the agencies, the advertisers and the publishers."
Marin Software provides clients with a paid search management application that can be used by advertisers and agencies. It is designed for firms spending £50,000 and more per month on paid search.
It has over 100 clients, including Razorfish and ZipRealty.