as long as we are speculating how about::
grading companies need to convince owners of sealed or CIB games that it's worth grading instead keeping raw. and the more grading companies there are the more you have to distinguish to your customers why 1 grading company is better than the other
there are so many ways to not pay for an auction, yet it still shows up as a "sale" or "completed listing". If you're an online seller for 1 month you figure out how much not_money there is inside of "selling" things online