Come on people use your noggins, it's possible because they don't subtract they just add!
What is 4.5 percent of 10 million damn near half a million people? At that rate they would add 2 million (give or take) every dacade. DO they? Fuck no, they are full of crap.
In fact they didn't even come CLOSE it's fudgy math! They aren't subtracting the people who LEAVE! It took them what 18 years to go from 7 million to 8? Why is that? Because when you figure in retention over time they actually grow by an average of somewhere from 80-90k a year. Still to much but a long LONG damn site away from a half a million new members a year, jeez...
And I think even that is lies, hell I think they are STILL counting my time and I've been a hardcore atheist/apostate for the last 5 years. Ridiculous all around.