Its an OK stat when comparing two different movies, released at different times, when you can take the average theater count each played in (theaters/weeks run) and use both to weigh the results for a proper comparison.
Now if you FUDGE the number intentionally by releasing in only 2 theaters in the most LIBERAL cities in the US, and then running around quoting its own 'per theater' amount... thats entirely different, and ANYTHING but a 'good' stat.
That's why I said if it's only in 10 theaters, it's pretty useless.
Actually, it's very good for comparing movies at the same time.
Any use of money as the measure over a long time (as HW likes to do) is fraught with problems. People attendence is never counted which is the only really good measure; so they use $ to make 100 movies look like they surpassed GWTW.