I am thinking of adding payment to my new service. I want to know what the difference is between subscription and one-off payment. My service is a survey website which would likely not be used every month so i was thinking of using a one-time payment with the full features for a limited number of days. what are the disadvantages?
Why are you giving potential customers an excuse not to use it every month? Are you basing this assumption on any real data? An obvious disadvantage is it could drastically reduce your revenue - Someone paying $10/month will remember to use our service regularly. Someone paying $10 for a one time use may find it expensive and even if they do not, may decide to go with a competitor the next time they need a survey.<p>Wufoo is in a similar business for the most part and are doing well with subscriptions.
In general, subscription services are great for things you'll need "once in a while". If you can get them on the hook for a low amount, it can be a great source of steady cash because they often won't take the time to cancel until way later.