Pay pal charges a small percentage on every donation, & a fee on every donation or transaction. So almost half or more of your small donations will be going to Pay Pal. If your donation is really small, the percentage & transaction fee may actually more than the donation itself, & actually cost me money.
With larger donations, the charges & fees are an insignificant amount. But if I'm only getting a few pennies after charges because it's a very small donation, or the donation is going to cost me more than the donation itself, I have to decline the donation.
I appreciate the thought, but if almost half or more of your donation goes to Pay Pal because it's so small, Or the fees cost me more than the donation, it doesn't make sense to accept it.
You can wait & save a few weeks or months so you can afford to donate a little more later. Besides, if your donation is very small, there's a good chance you need it more than I do.
On average, a $3 donation costs me about $3.10. So Pay Pal would get all of it, plus I would owe Pay Pal an additional 10 cents.
But for reasons too long to get into detail here, on average, a $10 donation only cost me about 74 cents, & a $100 donation only costs me about $3.20. So really small donations get proportionately charged the most, & are not helpful.