View your request count and decide what plan you need.
Every time a survey under your account gets rendered on someone's browser this counts as toward your request limit. By default you are given 2,000 requests on the free plan.
Requests counts are reset every month. If you exceed you limit the account owner will be sent a notification email.
All the survey under this account will stop being rendered for your users. At the end of the month, the limit will be reset and users will be able to see your survey again. If you increase your plan your users will instantly see the survey again until the new limit is reached without having to wait until the start of the next month.