The PC Gaming Alliance (PCGA) today released its yearly Horizons Report, a research study encompassing all aspects of the PC gaming industry worldwide. Among the key findings revealed by the non-profit consortium is that gaming software revenue was a $13.1 billion industry last year, up 3% from 2008. This total includes retail sales as well as online gaming, digital distribution and online advertising.

The report looks at some of the key trends in the PC game market. For instance, it's claimed that the transition to free-to-play games and the emergence of social network sites caused revenue to decline in some established markets. Subscription games suffered from the lack of major new releases, while boxed retail sales saw the biggest downturn of all categories and now account for less than 20% of all revenue.

Nevertheless, the downturn in established markets was largely offset by the growth of digital distribution. Most countries in North America and Europe saw revenue declines of 10-15% from 2008. But despite the worldwide recession, growth in the Asia Pacific region helped fuel the PC games market. You can find out more about the PCGA and the Horizons Report here -- unfortunately the full report is only available to paying PCGA members.