The move to Habbo, which is aimed at 12-17 year olds and has a presence in 29 countries, marks a return to youth entertainment for Guest.
He previously worked for Fox Kids Europe, where he lead commercial agreements across all areas of the business.
These included a partnership with Capital Radio's interactive division developing commercial partnerships to broaden the appeal of the Capital Radio Network, building on his previous stint at Capital's interactive division.
At AOL, Guest was responsible for brokering strategic alliances across all areas of the business including sales and marketing.
At Habbo, he will be responsible for all areas of the business, including advertising opportunities.
Users of Habbo join the social networking site by creating a customized character, called a Habbo. From this point, they can play games, connect with friends and decorate their own rooms.