Launched last month, Vartti.fi is a fledgling project that allows users to break news by uploading multimedia content direct to the site.
Vartti editors also publish story threads on the website and ask for multimedia submissions from the readers - setting them deadlines for their contributions.
The stories are then published in a series of ultra-local weekly papers distributed in and around the Helsinki area.
"With the Jokela High School shooting we had one of the first pictures in Finland [from the scene] which was taken on a mobile phone, we then sold it on to publications in Norway and Sweden," Janne Kaijarvi, editor-in-chief of Vartti, told Journalism.co.uk.
The site also broke news about a train fire in Helsinki, Kaijarvi added, with reporters first finding out about the incident when a passenger uploaded a picture to the site from inside the train.
However, the contributor for the Jokela picture was paid significantly more, Kaijarvi added. Sanoma publishes seven local editions of Vartti in Helsinki and a further seven in other areas.
Developers claim that 15 to 20 per cent of each paper is user-generated content. A figure they hope will be nearer 50/50 by next year.
"The market for these kind of news sites in Finland is very tough, we have tabloids which are very strong so we are trying to learn all the time what different approaches people may want," Kaijarvi added.
"By the end of next year the site might be totally different from what it is like now as we develop more and more user-generated content."
Vartti.fi is just one of five news site start-ups which have been launched Sanoma Digital, one of the largest Nordic publishers, since the start of the year.