The GPL explicitly allows you to charge a fee for delivery, service or whatever for your GPL-licensed code. There really is no debating that fact that you can legally charge for GPL software.

The only other argument here against selling GPL-licensed scripts is simply that some pirate or other evil-doer will nab your script and re-sell or freely re-distribute your application, making your pay-to-play model irrelevant. As a developer of a GPL-licensed application, access to which I charge a subscription fee, here are my thoughts based on experience:

1. If your userbase is largely noobs, they don't have the know-how to resell or re-distribute your stuff (setting up a site to do this is not for the beginner).
2. If your userbase is highly technical, they might re-distribute. Where does that leave you? Probably as the guy with the top hit on google which drives most people to your site for the product. This is especially true if you publish frequent updates and maintain a support forum for the application.
3. People will get your stuff for free, GPL or commercial license. It happens, get over it. If you think you can stop all the piracy, then that's what you'll be doing 90% of your time.

The post title is an important consideration. Since you are the code originator, you will be first out with the script and, being a savvy business person, you have a good SEO campaign underway to get you to the top of google. You will also be the first person with updates, and your site should have the best support forum for your product, as well as documentation. With all that, you will find many users appreciating your efforts and coming back for repeat business. Also, forum posts and online documentation need not be free and may be copyrighted so that you have legal recourse should someone try to simply copy your entire site.

My business model charges $5 for a 24-hour access window to download the plugin. Users might also select a $20, 1-year option if they want to come back often for updates or don't want the hassle of storing the plugin on their local computer. Other creative ideas to value-add to our subscription plans is to pre-bundle your plugin with drupal so that when someone installs your modifed drupal release, your plugin is also installed, configured and ready to go.

You will of course receive some flak from people who disagree with you. Most of these are due to inherent confusion regarding the rights, privileges and protections offered by the GPL. And there will always be people who want something for nothing and may complain. Don't let that bother you, it's all part-and-parcel of running a business. I went from 'free-GPL' to 'commercial-GPL, and for the most part people were happy to pay as little as $5 for access and also support future development. As a comparative note, less than 0.5% of people donated to the project when it was 'free-GPL'.

So, don't worry, be happy. Make your GPL-licensed script. Publish it on Drupal and sell subscriptions for access. Provide the source when requested by your members (in my case, i just publish the source but not the installation packages. Developers take it for free all the time, but most of my clients are noobs and pay for access to the installer packages).

Happy Publishing!

Anything Digital was launched in 1997 as a web design firm set to meet the growing demand by small businesses to have an affordable online presence. Victor founded Anything Digital and continues to manage the