BusinessWeek has a small selection of apps on their site that have shown an impressive performance and brought in more than a million US-Dollars in revenues. These are all really well known apps, most of which (if not all) have been international supersellers.

While the post does not mention whether these are just the numbers for the US-market or overall, it still leaves us thinking, if the full revenue potential is reached for these apps. We’re guessing no.

A million dollars is an impressive number, but it also means that all of these apps have sold to more than a million users in a matter of weeks or months. That’s a huge customer base. We can only image the size of the user base that could have been reached if these apps had been offered for free.

Why do this? Because in-app purchase for free apps now gives developers the chance to first engage users with their product and then up-sell within the app. So instead of charging 99 Cents (79 Euro-Cents) per app and selling a million copies, offer the app for free, reach a few million downloads and get the user to pay for additional goods and services (content, virtual goods) on a regular basis. After all, a customer base is an asset that should be used and interacted with on a long term basis. Developers like SGN now planning to offer one of their top sellers for free show that this might be the way to go.

Not only does this increase the customer lifetime value for a developer, it also incentivizes him or her to constantly improve the own app and provide constant value to the user, which in the end is a win-win situation.

Of course this may take some time, but we are getting there. If the trend goes on, we are guessing we will be seeing many apps that pull in a few million dollars or even more. Exciting, don’t you think?