It seems that the best way to maximize availability while also making fonts available for commercial projects is to offer different options depending on the type of use. So:
1) Personal Use. It is definitely not my intention to keep you from sprucing up your home scrapbook or Harry Potter fan site or what have you. Therefore, all fonts are free for personal use.
2) Basic Commercial License. If you would like to use one of my fonts for your business website, stationary, or anything else that a business might need fonts for (with the exception of the types of usage listed in paragraph three), purchase a basic commercial license. The prices are listed on the individual font pages and the license covers installation on five computers. Click here to view the end-license user agreement.
3) Additional Commercial Licensing. Additional licensing is required for (a) commercial product use, (b) broadcast or film use, and (c) software or electronic device embedding. To purchase an additional license, use the contact page to request a quote by sending a short description of the scope of your project.
This might not be the most technical and clear cut method of categorization so feel free to ask if you have any questions about where your project falls on the list.