Company name: mBlox
Where it's based: Sunnyvale, Calif.
When it was founded: 1999
What year it was a Fierce 15:
Website: www.mblox.com

Why it was a Fierce 15: MBlox was a dominant player in premium messaging, processing more than $500 million worth of transactions every year for leading content providers and global brands. The company, which grew from a slew of acquisitions, has billing capabilities reaching more than 400 million mobile subscribers worldwide. Click here for more.

What has happened since it was awarded the Fierce 15: MBlox said it continues to focus on mobile messaging, and has delivered billions of messages since it won Fierce 15 recognition. The company also recently announced the launch of its cross-operator Free to End User message service in the U.S., which the company said allows businesses to communicate with consumers using text messages that are free to the user. Further, mBlox said it has added several noteworthy clients, including MySpace, New York Times, eBay, MTV and MasterCard. Finally, mBlox said it expanded into Europe with a new office in Italy.