Pandora recently tallied their 200 millionth registered user according to a message on the company's blog. The streaming music service surpassed the milestone after more than 12 years in the business - far longer than most people probably realize they've been around.

Reaching 200 million users represents significant growth as the service just hit 100 million members in July 2011. Of the 200 million, 55 million are considered active listeners which has helped Pandora secure a spot among the top 250 most popular websites on the Internet.

But even still, the service has faced a lot of adversity in recent memory thanks to rising royalty fees. The company was forced to implement a 40-hour listening limit for free mobile streamers in February to help compensate although they said they noted at the time that less than four percent of active listeners would be affected.

The company, originally known as Savage Beast Technologies, was founded by Will Glaser, Jon Kraft and Tim Westergren in 2000. The team worked on building a music prediction and recommendation service that was eventually licensed to third parties like AOL and Best Buy but the venture nearly went under.

A new wave of funding in 2004 ultimately resulted in a name change and a restructuring effort that led to the launch of Pandora Radio in July 2005. The service has found success ever since albeit only in a few select markets. Pandora has had virtually no success in expanding outside of Australia, New Zealand and the United States - something they hope to change in the near future as they continue to try and break into a European market where licensing fees and royalties have thus far kept them at bay.