trialware

I am trying to implement a recurring subscription service on a website using PayPal however I would like to offer a free trial period before the user is billed and the subscription is started. Is this possible using PayPal's API? I have very little experience using the PayPal API and cannot seem to find any useful documentation about implementing a free trial period, so any help would be much appreciated. Thanks. Yes, you can do this. Recurring Payments - Documentation on PayPal website Trial period: An optional subscription period before theregular payment period begins. A trial period may

I'm developing a shareware desktop application. I'm to the point where I need to implement the trial-use/activation code. How do you approach something like this? I have my own ideas, but I want to see what the stackoverflow community thinks. I'm developing with C++/Qt. The intended platform is Windows/Mac/Linux. Thanks for your advice! What to protect against and what not to protect against: Keep in mind that people will always find a way to get around your trial period. So you want to make it annoying for the person to have to get around your trial period, but it doesn't matter if it's

I have created my product and also generated license key for that but I want to ask that key after 30 days. I have do it with registry value storing the date with adding 30 days in that. But I found that if the user change the system date with 30 days before my logic not work. So is there any solution for the trial version software without checking system date and allow only 30 days of trial? You could have another registry key that you increment after every day's use. That way, even if they change the computer's date, this key would indicate to your program that it's been running for > 30

I have an application which I want to hit the market as a Paid app. I would like to have other version which would be a "trial" version with a time limit of say, 5 days? How can I go about doing this? Currently most developers accomplish this using one of the following 3 techniques. The first approach is easily circumvented, the first time you run the app save the date/time to a file, database, or shared preferences and every time you run the app after that check to see if the trial period has ended. This is easy to circumvent because uninstalling and reinstalling will allow the user to have