
Campbell Lace picked up the business following a shootout against Publicis.
The agency will now work on creating campaigns that aim to encourage new players to visit the JackpotJoy Bingo site, raising awareness of the variety of games on offer.
Launched in 2002, JackpotJoy Bingo has quickly become one of the leading online gambling sites in the UK, with the annual pay-out of winning bets now exceeding £75 million.
The company has since launched several games based around well-known TV game shows such as Deal Or No Deal, The Price Is Right and Family Fortunes, to go alongside its regular bingo and casino games.
In recent months, Gamesys has also signalled its intention to enter the European market, with the launch of juegatusuerte.com in Spain.
The appointment of Campbell Lace is the agency's second win this week, after it picked up its first account, Thomas Cook, on Tuesday.
The agency, which was founded by Garry Lace and Robert Campbell in April, beat Euro RSCG London to that business.