Pandora reached the milestone of 200 million registered listeners Monday.

The announcement came about on the company's blog by co-founder Tim Westergren said, "We are very excited to announce today that Pandora has reached 200 million registered listeners!" He added, "When we launched https://www.pandora.com in 2005, we hoped to create a new way to discover and enjoy music that was completely personalized for each and every listener.  We envisioned a time when artists of all kinds would thrive on radio, connecting with fans who loved exactly their kind of music."

Pandora is an automated music recommendation service and "custodian" of the Music Genome Project. The service is operated by Pandora Media, Inc., which is available in the U.S., Australia and New Zealand.

If for example you type in the artist Drake, that becomes a station. When you play that station, you'll hear any music that is a Drake song, another artist affiliated with Drake, music similar to his and music that Drake listens too. You can have as many stations as you please, which include artist, bands, genres, comedians and more.

The 200 millionth registered listener comes nearly two years since the company reached its 100 millionth registered user back in July of 2011, according to digital trends. Pandora went public in 2011. The 200 million registered listeners, more than 55 million active users, and a place among the top 250 websites on the internet, Pandora has accomplished a lot in recent years.

"I have to admit, we had no idea what was in store! It has been, and continues to be, an extraordinary experience for all of us," Westergren said in the blog. "A hallmark of these years has been the steady stream of amazing stories from our listeners, whether they got engaged while listening to Pandora, mourned the passing of a loved one, or celebrated a special life milestone."

According to Digital Trends, royalty fees continue to cut into the company's revenue. The company went as far as to limit users to just 40 hours a month of mobile listening back in February unless they opt for a $36 per year Pandora One plan. This was done in order to curb heavy users who are mobile, and only receive a fraction of the ads that desktop users see. While advertising still accounts for more than 80 percent of the company's revenue, the addition of subscription options have helped curb some revenue concerns for the company.