The base annual price for the Cloud service is $250 per service, which covers the service usage up to 50 million words per year. The services calculate the total number of words, which were processed, no matter their correctness level.
However, there is one thing that you should keep in mind for the SpellCheckAsYouType (SCAYT) and WebSpellChecker Proofreader products. There is a mechanism of “caching/remembering” previously checked words during this active session (until the page reload). Thus, the products remember already checked words and won't send them again for spell checking
For example, if you have text something like “Hello, how are you ” and the user adds at the end of the sentence a word “today”, so a new sentence is “Hello, how are you today”, then the only one word “today” will be sent to the server for checking.
After that, the user adds “. Hello” and pauses for a few seconds, so a new sentence is “Hello, how are you today. Hello”. In this case, SCAYT and WebSpellChecker Proofreader don't send any requests as all these words have been already checked, and we know that “Hello” is a correct word.
You can check your usage statistic for the previous month and since the previous payment date on your subscription account. When you sign up for Cloud services you receive “WebSpellChecker subscription” email. There you can see your credentials (customer ID and password) to login to the subscription page on WebSpellChecker.net site: http://www.webspellchecker.net/account/login.pl
