The phrase "opportunities for coercion or vote buying/selling" in the above post refers to opportunities for a malefactor to be physically present while a voter is filling out the ballot and coerce/bribe the voter to fill out the ballot a certain way. Voting at a polling place guards against this by requiring that the voter cast a ballot privately, out of the view of anyone else.

You don't sign the ballot. You sign a paper that gets sent along with the ballot. If things are done properly, the person checking your signature doesn't see your vote and the person counting your vote won't see your signature.

Yea I wasn't totally accurate in my response. The point is, voter fraud by mail requires accurately forging a LOT of signatures.

Alternatively, the state can pay for the return stamp, but will likely have to pass some tax measure to fund it (in Oregon, state budget must be balanced), so in the end voters would still be buying the stamp. This is less efficient since now there would be stamps bought that folks have no intention of using since they drop them off.

No need to forge signatures, you just order all your kids and grandkids to vote like you say, or they will be ostracized by the rest of the family.

Or you order all your employees to vote like you say, or they will be fired. If they don't snap a pic of a ballot filled out to your liking, out the door they go.

Or you just buy the votes of anyone. $50 for a pic of a "correctly" filled out ballot. That scales pretty nicely.

I see your point, but don't agree that it 'scales pretty nicely' since it would rely on all participants keeping quiet about it, which definitely prevents it from scaling at all since you won't be able to openly advertise you are doing this without drawing fire from election officials.