Rounding to the nearest hundred? But yeah, these ties seem a little suspect.
I would guess rounded out to at least 500 units, or even more.
My app on the appstore continually swaps places with other apps that have similar sales rates in the top grossing and top paid lists. I wouldn't personally go out on a limb and say other company x's product was selling more than third company y's product unless there was enough gap for that to remain true for a day or two.