Typotheque offers three different ways of using fonts on the web. Hosted Webfonts is the simplest option, ready to use in minutes. Clients receive CSS code for using fonts online, and manage their project via Typotheque online account.
When reaching the limit of free 500MB per month, you will receive an invoice at the end of the month for the bandwidth that go over the free limit. There is currently no way to pre-pay the bandwidth, you receive an invoice after exceeding the limit.
For the hosted fonts you pay a one-time fee for the font licence. If you stay within the allocated bandwidth limit (500MB per font per month), there will be no further costs for you. Additional bandwidth costs €0.001 per megabyte, per month.