“Don’t use a five-dollar word when a fifty-cent word will do.” Those are the very wise (fifty-cent) words of Mark Twain, not just a celebrated writer but also an entrepreneur and investor. His investments didn’t fare too well, but he did fully master the economy of writing.
What Mark meant was that if you have the choice between an uncommon term like “sesquipedalian” and an everyday word or combination of words such as “long-winded”, which means the same thing, you should always choose the everyday word. The goal is to focus on clear, concise communication. And in prose as in business, the tactic will create a valuable connection with your audience that no amount of sesquipedalian words will.