The Episcopal Church, USA, claims to be a denomination of 2.4 million people. That's the number you always see in newspaper reports.
However, the average Sunday attendance of Episcopal churches in the USA in 2007 was 727,822 people. If you include all of their foreign churches, the average attendance was 768,476. The average attendance across the Episcopal Church in this country has gone down 12% in the past 4 years. I could not find one diocese in the entire country with a growing number of people on Sunday mornings.
If you are interested in more statistical information about this, you can find it here.
OK, so the new Anglican Church of North America claims 100,000 people. I would be interested to see where they/we get that number. Because that sounds pretty high if compared to the actual numbers of the Episcopal Church. Of course, I have a feeling that this number may be wishful thinking, like the Episcopalian's "2.4 million."