As you've said, why pay, when you can use the free version on-line? You have to give them something for their money. You have to differentiate between the free version and the one they pay for.
Graphing is one option, but you'll need to think of more. There's also the problem of people paying, downloading, and then giving it away to others. Do you not worry about this? Or do you somehow "lock" the download to that user. Be very, very careful about preventing someone for using something they paid for. If their machine breaks and they get a new one, with the program still work? How can they move it?
And so on.
The real point is that people will only pay if they get something in return. Think carefully about what that might be.
Yes, these are all good points. I really want to find a way to keep the online version for free. The advantage of the download (desktop version) is that users can run in a borderless window with six color schemes and the ability to close the side palette.
I'm sure there are many students in poor countries that enjoy having a nice powerful online calculator that is easy to use, but nice is not a good business model.
We don't have a good way to prevent pirating and my thinking was that even top products like Adobe get cracked pretty quickly and distributed (so I figured it was a lost cause...)
Anyway, we have plenty of great ideas for additional features that we can add into the palette. Maybe we make a "pro version" that has these extras...
>The advantage of the download (desktop version) is that users can run in a borderless window with six color schemes and the ability to close the side palette.
Is this really an advantage? I'd want to confirm with potential users that they are concerned with color schemes (as I know I'd never pay for color) and having it in a borderless window as opposed to an additional tab in an already open FireFox.
You really need to define the additional advantage of the pay vs non-pay version. What is the screaming need in your users lives that paying $15 is going to solve?
Yeah, maybe we need the "Super Pro" that includes Graphing and other cool features. Or take away some online features and wrap them into the "Pro Only" package.
Graphing is one option, but you'll need to think of more. There's also the problem of people paying, downloading, and then giving it away to others. Do you not worry about this? Or do you somehow "lock" the download to that user. Be very, very careful about preventing someone for using something they paid for. If their machine breaks and they get a new one, with the program still work? How can they move it?
And so on.
The real point is that people will only pay if they get something in return. Think carefully about what that might be.