$100 may not be much, but if you are constantly churning out $100/month side projects and working very little to keep them up and running, that turns into big money fast.

On a side note, I must admit that at $19.99, I would not buy an app with the sole purpose of cleaning out my Twitter inbox -- maybe I'm not the target audience, but that seems like a lot of money for something that does a very specific task -- one that could be easily implemented by Twitter at a later time.

Of course, that assumes the main goal of the app was to earn money. The knowledge gained from creating it could very well be worth it.

Thankfully, the support costs are, err, maybe an email every few months? Basically, extremely low. Combined with sharing the hosting with TweetingMachine, it is essentially all profit at this point :)

  it is essentially all profit at this point

Now it's time to build another $100/mo success until you get enough of them to buy that private island you're always wanted...

Otherwise, I agree with the rest of your comment.

But I think if someone is industrious enough to support that project for an hour a month, they are industrious enough to use that hour some other profitable way, though. It's unlikely they would just sit on their thumbs and wish they had something to do.

$100/month is not a lot of money, but creating app that makes $100/month from nothing is much much more harder than polishing this app to bring $200 (or even $500) per month.

You have the wrong approach. You can't predict success and you can't predict what markets will work and you can't prredict what the perfect product for a market is. You have to release products and track ALL possible metrics and tweak consistently.

Basically, even the really big companies have hits and misses. And more misses than hits.

So, firstly, you should be releasing 5 or 10 high quality web apps and seeing which stick and focusing on the ones that do.

That's the first step - finding a market demand.

Second is hitting the value for money/quality/perfect market fit.

That's the second step - after you have found market demand, making the most of it.

An inbox cleaner for $20 is just too expensive. Too much friction - especially for a new product from an unknown developer. You have to minimize regret for users - or rather, potential regret.

Instead of thinking in terms of what you want to make think in terms of what people want to get in terms of value for money. 5 people is too small of a data point. So you have to lower the price anyways - to get enough customers to find out whether there is market demand or not and what things people want and what they are willing to pay for.

So play around with the price a bit. Plus release 4-5 other products and see if you find a market with huge demand - one where even lower value for money sells well.

Previously, I have charged $4.99/year, $19.99/year, $1/month, $4.99/month, and $19.99/one-time is the latest price. You're right that the sample is too small to make much of... on the other hand, it is double what the tool usually makes per month.

I'm happy to experiment, my main question is: am I missing out on the bigger picture by charging for this app instead of using it to promote TweetingMachine? I'm not convinced that the target audiences are the same... but guess I'm going to have to do another experiment ;)

Even then, you could argue it's better to build multiple streams of income and not depend on one product.

An offer of Buy 1 product and get the other free - that's fine. But giving away inbox cleaner doesn't make sense unless you get a really high conversion rate for Tweeting Machine.

You have also asked a completely different question in your blog post. To sell more tweeing machine subscriptions - perhaps a longer trial (1 or 2 months instead of 10 days) or a lite version would make sense.

A way to indicate whether it is a failure or not is whether or not it continues to grow, if you're targeting a very specific market it is very unlikely that you will earn a lot of money (I personally don't have that much amount of email that I need InboxCleaner to do some job for me...).

If however it is an awesome thing, people will get to know it and start using it, then it won't be a failure.

I was previously charging $4.99/month, and before that $19.99/year. So far, the one-time fee is winning, although I'll be interested to see if that continues next month ;)

Quick edit: Right in the early days, I experimented with charging $1/month and $4.99/year, just to see what'd happen. End result: a lot of nothing. Still not sure what to make of that, other than people don't want to pay for the service ;)

I'm currently experimenting with various marketing efforts), and they do sometimes seem like an uphill effort, with very few definite answers other than "Experiment and see!"

I'm trying to work out how far to experiment with this one, and will keep on writing updates as they happen :)

Assuming that's the case, scale your app so it brings in more (it's already proven itself) ~or~ put it on the backburner as a "passive income generator" and go hard on something that will bring in real money.

For instance, I haven't updated one of my iPhone apps in a few months, but in the past week or two my sales for it have been better than I normally get in a month. Sometimes it gets better, and you just have to let it grow.

To be fair, it's not that new - it's well over seven months old at this point :)

I myself not having a profitable app on the store would see it as a success.

Granted, you would need quite a few apps at that level a earnings to make a living.