SitePal can handle any number of concurrent viewers (website visitors).
The service is CDN accelerated with edge servers worldwide. Services such as dynamic TTS are cloud based and scalable.
The infrastructure is the same as used by Oddcast (SitePal parent company) to deliver superbowl campaigns & annual ElfYourself holiday greetingcard/experience which is viewed by hundreds of millions of visitors over the holidays.
Hope this helps, best,
as we are using dynamic text to speech ,i have found this link that states 5 concurrent users, http://www.oddcast.com/user/terms_of_use.php
Thanks for pointing it out. The terms are under review and will be updated soon.
Customer support service by UserEcho