1. Community edition - no direct support, maybe some enterprise features no available (like Sencha.com)
2. Hosted version - easier to PAYG with a lower price point per use (like Typekit)
3. One off purchases with updates for just 12 months. Updates then require licensing (like Sketch)
The other option is that you only got for enterprise and exclude the startup and indie developers. Enterprises tend to have no issue doing the right thing. If you're worried about smaller developers taking advantage, then you need to weigh up the long term benefits.
Just remember, if it's hard to do, it doesn't automatically make the wrong choice the right choice.
- One: the model you have right now. this is for organizations where the value outweighs the price tag.
- Two: Smaller organizations are generally also more willing to compromise on JS/asset bundling and performance. Why don't you give them: - a hosted JS solution where they just have to include a <script /> tag - An uglified script. I'd argue most JS developers can't unscramble these - you keep counters on number of requests - you disqualify (using some basic hashing method) run-ability of PDFJS Express based on the time the script was requested OR if an acknowledgement from a server fails. So say, if someone is using a cached version, the script will either not run at a certain point OR all the documents will be watermarked with "TRIAL".
This second way could also be the best way for getting people started immediately. Include a tag, see a watermark, but you are ready to go.