Mitchell Baker has posted the details on Mozilla’s financial performance for 2006 and it is more good news. Revenue was up around 26% to $66.8m, while usage is also on the up.

Expenses increased from $8.8m last time out to $19.8m, although revenue growth outstripped expenses growth, and the majority of that went on people and infrastructure to support the project’s growth.

According to Baker, “By the end of 2006 Mozilla was funding approximately 90 people working full or part-time on Mozilla around the world.” Expenses can be expected to rise again next year “as we have continued to hire and fund more people and develop additional programs,” she adds.

Infrastructure investment is spent on ensuring Mozilla can meet demand for Firefox. “In late 2006 we served close to 600,000 Firefox downloads, over 2.1 terabytes of data and 25 million update requests – per day – making Mozilla one of the top 100 sites on the web. In addition, 2006 saw a vast increase in capacity and infrastructure reliability for all essential Mozilla services including the launch of a European data center, cutting server response time by 50% or more for much for Europe,” baker reports.

Of course most of the revenue came via Google, although interestingly the more Firefox users there are the more usage growth is likely to outstrip Google revenue growth as the rate of payment declines with volume.

For more of Mozilla’s revenue, including where it comes from and what it is spent on, take a look at Baker’s full update.