Every Sparkle account starts with a 30 day free trial. This means you can see for yourself everything Sparkle does, so you can make an informed decision about whether to use Sparkle.
If you cancel your Sparkle account within the first 30 days, you won't be charged. This gives you a risk-free way of assessing Sparkle for yourself.
Once you cancel your Sparkle account you won't be charged again, but any charges you have already been invoiced for still stand. For example, if your invoicing cycle is on the 14th of every month, and you cancel on the 23rd, you'll still have to pay the invoice you were sent on the 14th, but you won't be charged again after that. In order to treat everyone equally, no exceptions will be made.
You can cancel your account at any time by logging into your account and selecting the Account tab (you need to be the account administrator to see this). Once you are on the Account page, click the "Please cancel my account" link.