Mr. Sampo Karjalainen (29), is responsible of the concept design and look and feel of the original versions of Mobiles Disco and Habbo Hotel. Mobiles Disco was a non-commercial predecessor of Habbo Hotel launched in fall 1999. It was a browser-based graphical chat environment with a distinctive visual look and feel and it became a small online phenomenon within some months. Keen to develop the concept further, Sampo Karjalainen and Aapo Kyrola joined Helsinki-based advertising agency Taivas and developed an online game "Lumisota" (Snow War) with the agency. The campaign game was awarded "The most innovative and fun web application" prize in Scandinavian Interactive Media Event (SIME) 2000.

Sulake was founded in May 2000 and with altogether four employees, including Karjalainen and Kyrola, the initial version of Habbo Hotel was built and launched in Finland in August 2000. It turned to be a success both in the number of visitors and industry competitions (e.g. Grand Prix in M&M Grand Prix 2000, Platinum pixel in RE:spect The Big One 2002, Golden Nica in Net Exellence in Prix Ars Electonica 2003).

In May 2006 Habbo Hotel has been localized for 17 countries and the company employs over 250 employees. Habbo Hotel has become one of the most popular teen websites in the world. Over the years over 51 million Habbo characters have been created and on monthly basis Habbo has 7.1 million unique visitors (Source: Nielsen/NetRatings SiteCensus, April 2006). Today Habbo, as a brand, is expanding outside the hotel, into other platforms, containing mobile, animation and merchandise. As the Chief Creative Officer, Karjalainen is responsibe of the concept and visual design in the company. He also runs the Research and Development team which works on new game and online community concepts in their early stages.

Before Sulake, Karjalainen has worked in pioneering new media companies of Finland: To the Point (1994-1998) and Satama Interactive (1998-1999) as a graphic designer and and animator.