The following website delivers genuine industry figures and trends by recording and tabulating Poker tournament buyins for a select portion of the industry. These figures don't include cash games but they do give an excellent insight into the growth of this hobby.
By joining up to their monthly newsletter, you will be kept abreast of the general trends on a regular basis. In summary, the news is all good with a growth rate of 36 percent for the year so far!!!
A good return for any investor.