A pharmacist assists a customer. gradyreese/iStock via Getty Images The formula for successful long-term investing is pretty simple. Quality plus a reasonable or better valuation plus time equals vigorous total returns. I've touched on what I mean by quality in past articles, but please allow me to reiterate: A track record of consistent earnings growth. If a company grows its profits just about every year, this is probably the best indicator that the business is well-run, and the business model is viable. ...