Shareholding
This was another idea from one of Anarchy Online subscribers, as Funcom was floated on the stock market in Dec 2005. In this instance, the customer was a regular investor, but of course anyone can purchase shares, and the MMOG industry is a fast growing market.
If the company is listed in your currency, you should be able to arrange purchase through your bank; the process is country dependant - otherwise you will need to go via a broker. There are several online, but take care to check fees.
At the least, shares will give you another channel to communicate with the business through, and potentially a vote if it's voting stock. At the most, enough shareholders could theoretically form a lobby group to have a more significant say in the games they already invest time and money in.
As with the majority of this site, if there is enough interest, the web space is available to support it. A forum would likely be the most efficient way for shareholders to organise and discuss should there be enough, and the necessary expertise and skill set exists to administer and guide such an initiative.