Commonly called freemium:
a business model by which a product or service (typically a digital offering such as software, media, games or web services) is provided free of charge, but a premium is charged for advanced features, functionality, or virtual goods. Wikipedia entry on freemium
From the blog post at ADN HQ:
Although App.net has had only paid account tiers thus far, we initially conceived of App.net as a freemium service. It took some time to get to this point, but we are now ready to make this vision a reality.
Free accounts are limited in the following ways:
- Free tier accounts can follow a maximum of 40 users.
- Free tier accounts have 500 MB of available file storage.
- Free tier accounts can upload a file with a maximum size of 10 MB.
Here's a couple of invite codes to try out for yourself if you're interested. First come, first serve:
I'm iChris over there if you're on.