3 ways to acquire cards: Buy them, Trade for them or Have them given to you.
There are many places to buy them. COMC, Sportlots and Craigs list was left off of the poll along with others.
There are many more trading sites then just TCDb. TCDb is the best but there are others.
Some of us are lucky and have had cards given to us. More than we wanted.
For me it is any where I can find cards as I'm only picking up cards for my PC. When others may be picking up cards to sell or trade. So this month/year they/me may find more cards in one area and next time it maybe another area. So over what period of time are we talking about. I take it "As long as I have been collecting" but how I'm doing it today is different from 5 years ago.
Some too bad there was not a choice of "anywhere I find them" slot.