Before understanding the best option, you should examine your user base a little more.

10K a day sure, but what's the breakdown? Do you have 2K that visit the site 5 times a day, every day? That lends itself well to the subscription model. Are most of your visitors in and outs from google, with no recurring vistis? Ads might be the better option here. Are most of your visits coming from .edu domains? There may be an opportunity for school sponsorship here. Etc, etc.

You need to fit your monetization model to your particular user base.

That's great information. Does Google Analytics break down if they are coming from .edu domains or do I need more powerful analytic tools? Thanks

I'm not sure to be honest. I think it may. You're basically looking at a reverse DNS lookup, and that's not exactly accurate, but might put you on the right path.

Maybe throttle the number of advanced functins or calculations unregistered users are allowed to do per day (or session, or other time period) and have a countdown/tracker displaying the number they have remaining along with a link to register.

Buy the desktop version, get unlimited access to the web version.

Put an identifier cookie on their machine and display the number of calculations performed over all time along with a link to the purchase. You know, guilt.

Maybe have a few of the more esoteric but ridiculously useful functions disabled and only enabled either in the pro or just by viewing a nag screen - click sin and get a popup (the first time this session only) that says "We're glad you like this, hey there's a free version). Only nag them a very small percentage of the time, but every now and then nudge them a bit.

Wonderful Ideas... I'm thinking of trying just a nag screen to start that shows "buyNow", "free trial", and "continue using online"... If people still don't purchase it, then I will have to punish them more....

I suspect some users might prefer a paid advanced version online instead of having to download a desktop app. You could either try a monthly subscription of $1 or a one time fee the same as your downloaded version.

To see which wording of "BuyNow" or "free trail" etc works best you should do some A/B testing using something like Google Web Optimizer. Hopefully it will speed up the process of finding the correct wording/strategy/layout.

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?

Isn't the $15 download already the "pro" version?

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.

- Analyze what calculations your users are doing and serve related ads. Example, for someone doing compounding interest 12 times, you show books related to investments. Or someone using some mathematician work, a link to his biography book;

- Contact a company and ask if they want to sponsor a contest. The first 5 users to complete some math problems will earn whatever the company is offering (essentially that's an advertising campaign for the company);

- Run a contest between your users. They pay 5 bucks to enter, and the winner gets the money (after your share ;). A tournament perhaps?;

Sounds like some great geek stuff... thanks.

There are already graphing sites out there, but they're more data oriented than calculation oriented (not sure if that makes sense). But basically if you could hook the calc up to a graph and make them really easy to create and share you would be able to get some virality. If you had a ton of graphs out on the web with ads on them you (like millions of them) you could make some money.

Great Idea. InstaCalc.com has this sort of thing for sharing spreadsheet like calculations.

Seriously, if you have that much traffic, just use adsense.

And kill your downloadable product - it serves no purpose business-wise except to tempt you to take steps that will reduce your traffic and by extension your ad revenues.

We've tried using Adsense and the payout is really bad. I can't post specific's but selling one calculator a day is a lot more revenue that any adsense we've seen.

I'm thinking that the word "calculator" may be too generic for adsense and so we are SOL in seeing that as a revenue stream...

iPhone app?

This is a valid idea - though there are already a ton of calculators on the iPhone store and so we'd be competing against a saturated marketplace. One reason we did this project was the fact that most online calculators have terrible user interfaces and don't support things like complex numbers, or a traditional stack.

Just because there's a ton, doesn't mean its saturated. Moreover, do the owners of those apps have the ability to direct 10k users daily towards downloading their app? I would seriously look into it. Same with Android. Its silly to dismiss the iphone just because there are competitors. You can kick their ass even though they were first.

Edit: I should also add, the iPhone/mobile apps would likely far outstrip the sales of the $15 download, because people are used to buying iPhone apps, and Apple has made it much easier than buying from you. I would even suggest reversing the flow, so to speak, and talk about how iPhone users can find a free version online from their home or work computers whenever they want.

Good point. We created this calculator using just JS and CSS so it should be really simple to port to the new Pre, which is our plan. However, our background is not in programming so starting up iPhone programming might be a bit of a trip...

Have you considered who/how you're marketing this to? Maybe you could find a way to target engineering and science students. What does the $15 version offer that the online one doesn't? That wasn't immediately obvious to me, but I didn't look to long.

How does the calculator handle something like solving a matrix of complex numbers. I had to do that a lot in linear circuit analysis and would have loved a better tool to do it with.

The desktop version runs standalone in a borderless window and includes six color schemes and the ability to close the side bar. My background is in EE, so we designed the linear equation solver to handle complex number (both in polar and rec format) which is perfect for solving circuit problems. So you can enter in your mesh loops and solve for various complex values. We'll have some documentation on how to do this, but basically if you have a set of simultaneous equations with complex coeff you can enter them in each box and solve for the answers..

OK, one more comment, then I'll stop. :-)

Does the desktop version do all the math functions of the web/free version? Most EE types aren't too into closing sidebars or color schemes. I guess if I was a student and there was some sort of teaser, like a way to ease the pain of linear circuit analysis, I'd probably buy.

I wonder what other stuff you could add to mess with competing iPhone apps. I'm a Luddite Blackberry owner, so I don't know quite what's out there.

We have plans for more cool EE features, so that's a bonus. Right now it's more general purpose so we could get a nice first release out. Maybe we'll see some traction if we market it more toward engineers.

can try going for affiliate links for graphic calculators, but I don't think it'll monetize that well

We tried creating a calculator store and linking to Amazon, but the conversion is pretty bad there as well. If people are looking for an online calculator they don't real want a handheld... Thanks for the feedback.