How many people are Scientologists in the world?

Scientology claims that there are approximately 8 million Scientologists, world-wide. However, Heber Jentzsch, President of the Church of Scientology, admitted in a TV interview that this number includes every person who has ever purchased a book, taken a service or otherwise shown any interest in Scientology whatsoever. Third-party sources have estimated the number of active Scientologists as 55,000 in the US, 1523 in Canada, 741 in Australia.