The first mobile operator in the world to be funded through advertising, Blyk, has doubled its number of members to 200,000 since April, Reuters reported Wednesday.

The Finnish company was launched in the United Kingdom in 2007 and provides 16- to 24-year-olds with the opportunity to send 217 free text messages and 43-minute-long phone calls in exchange for receiving six advertising messages daily.

"In the context of the hundreds of millions of mobile phone users in Europe, its subscriber base of 200,000 in the UK seems small but it's a highly focused target market," said research director of CSS Insight, Ben Wood, according to reuters.

Blyk CEO Pekka Ala-Pietilla said that the company had the highest response rate for the lowest cost out of all advertising mediums, with a quarter of those who receive the ads responding and bringing advertisers 50 pence (US$0.89) per reply.

The firm currently works with brands like Coca-Cola, L'Oréal and Sky in order to promote ads to a younger audience that show interest in them, Reuters reported. The service is set to launch in the Netherlands by the end of this year or the beginning of the next and is expected to be released in Germany, Spain and Belgium in 2009. The potential market may make up nearly 24 million 16- to 24-year-olds.

“Blyk's operations are closely watched by traditional mobile carriers struggling to find replacements for dwindling voice call revenues but most are still working out how to devise suitable campaigns and how to split the revenues with partners,” the Reuters report stated.