[babuskov]

I find time limited trials useless. For user, it is inconvenient, because maybe the time is not enough to test complex software. For developers it's bad because user can simply reinstall the software again when trial period is over.

In my apps, I limit the amount of data you can store in trial version. So, you can try it as much as you can. For example, if your software was an e-mail client, you could limit it to 30 messages in any folder (inbox, sent, trash).

[SyneRyder]

Depends how you do it. Many apps that use time trials will often leave behind some preference file or registry key to block re-installing.

But it's probably not worth building that into your software (I don't) - customers will either get so sick of reinstalling every 30 days that they just buy your software, or they're so poor that they were never really going to be a customer anyway, so you may as well let them continue with the workaround until they can afford it.

Time trials can be useful though. While most customers buy within the first day of use (and typically the first hour!), anyone who tracks metrics knows that expiring the trial version also generates a boost in sales around day 29 / day 30 of the trial.

[flybirdx101]

I am not sure that this can be applied to any kind of app. You have to give user as much as possible until the product becomes valuable enough for him to buy, and that's when update option should be displayed. For example, in the case of an email app, time-limited trial can actually be a better option. User get's used to it, maybe he stores some additional information inside it or uses some specific features. Just limiting a number of emails would not let the user see the full potential of the app.