Advice iz a drug in the market; the supply alwus exceeds the demand.

[Advice is a drag on the market; the supply always exceeds the demand.]

Josh Billings (1818-1885) American humorist, aphorist [pseud. of Henry Wheeler Shaw]

Everybody’s Friend, Or; Josh Billing’s Encyclopedia and Proverbial Philosophy of Wit and Humor, “Lobstir Sallad” (1874)
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