To pick a number, perhaps at least a $5,000 a month minimum transaction volume, but more likely $15-20,000 monthly transaction volume.
Well of course ....if you were earning $20,000 a month and still using paypal I'd be slightly worried, however claiming that businesses earning less that x thousand dollars per month are not "true businesses" is slightly naive (and offensive).
For all you know I/Andy could be self-employed and $5000 a month is a decent income ($60,000/p.a) to live on and we would be paying income tax and all other necessary taxes...so that means we aren't real businesses? ...I certainly don't agree.
A sole trader with a tiny corner shop is a business just as Microsoft is, yet they earn billions more.
Fair enough, paypal may not be suitable for larger businesses but as you said you were speaking from personal experience, as were Andy and I.