One of the problems with mobile app markets is that customers are often forced to purchase an app before knowing its true quality. That’s why reviews are so important in the various major app marketplaces – they allow users to learn from the experiences of others and decide whether they want to purchase an app or not.

Now Amazon is adding another layer of consumer control to their app purchases. In its Amazon Appstore, the online retailer is allowing users to test-drive mobile apps on their smartphones and tablets before buying.

As Engadget reports, the beta test version of Amazon’s Test Drive software just became available in the Amazon Appstore Android app. It’s not an entirely new feature to Amazon’s marketplace. Previously, users could try out apps on their computers using a version of Test Drive that worked in web browsers. But the update makes that same experience possible on the very mobile devices on which the apps will appear via an Internet connection.

While Test Drive for mobile devices is definitely a step forward for the Amazon Appstore (and app purchasing in general), it’s not available for every app or every mobile device. Engadget struggled to find any apps it could test with a Samsung Galaxy S II, for example, so don’t expect the feature to be incredibly widespread just yet.

Still, hopefully Amazon’s Test Drive feature will be something that Google and Apple emulate with their marketplaces on a widespread basis. Demos for apps could have some very positive effects for users, allowing them to know exactly what they’re getting into before they purchase apps, especially if there’s no free or ‘lite’ version available. A $4.99 app might be a hard sell for developers when all they have to convince potential customers is a text description and some screenshots, but a demo lets users see features in action, and Google Play’s 15-minute refund window is hardly enough right now.

The demo feature is a positive for developers and for app discovery in various markets, and it may also help with the issue of app pricing. Many have cited the low cost of apps, especially mobile games, as driving down the price of other games because players get used to paying so little. Demos can help justify higher prices by giving players an idea of what the games are like before they commit. It could make higher-priced, higher-quality games more viable options. That might be a little bit of wishful thinking on my part, but it’s hard not to be positive on any feature Amazon and its competitors might use to help inform customers before they make a purchase.

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