Thirty years ago, Ken Fisher burst on the investment scene with his book Super Stocks, in which he showed that investors often focused too much on earnings while ignoring sales and other metrics. Three decades later, Fisher says investors haven’t learned their lesson.

“Always own some stocks of profitless good firms,” Fisher writes in his latest Forbes column. “Some are turnarounds. Others fund growth through legally deductible futuristic expenses that mask profitability while avoiding taxes. Both needlessly confuse and scare off most investors, who are guided solely, mostly or too much by earnings.”

One example: Amazon. “More and more it simply dominates retailing,” Fisher writes. “Whatever it is, if it isn’t on Amazon you probably don’t need it (except securities — and probably even them soon). Don’t believe me? Try searching for bizarre esoterica you expect only in a niche specialty store far, far away. Profits later; dominance now! Amazon is an ‘old tech’ name yet merely 21 years young, barely drinking age. As such, this huge category killer fits perfectly into my vision of ‘old tech’ leading this bull market’s golden years.”