The 1099-B instructions read:
"A broker or barter exchange must file Form 1099-B, Proceeds From Broker and Barter Exchange Transactions, for each person...."
AND
"A broker is any person who, in the ordinary course of a trade or business, stands ready to effect sales to be made by others."
A company that REGULARLY redeems its own stock can be considered a "broker" even if the company isn't a registered "broker" in the usual sense.
Most "private" sales don't result in a 1099-B unless a real broker is involved.
