People have a propensity to overconsume free goods.

Whether it's buffet food, healthcare services, or zero-commission trades, they take as much of a free thing as they can.

I used to trade stocks with a discount broker. Not long ago, I moved that money to a full-service broker.

This Move Improved My Trading Dramatically

Knowing that I have to pay commissions prevents me from overtrading. Plus, the added level of service I get when I do want to trade is worth the cost.

With my full-service broker, I do all my trades over the phone. The reason for that is accountability.

Someone on the other end of the phone hears me put on the trade and take it off. If it's a loser, someone else knows that I made a mistake.

On an online trading platform, you lose money anonymously. You don't ever have to share with anyone that you lost money.

I am a fan of having my trades public. I announce all my trades in my newsletters. If there is a loser, thousands of people will read about it. No one likes to lose money, but no one wants to be embarrassed.

Most people would rather lose money than be embarrassed. Being embarrassed is being accountable.

Why pay for something that you can get for nothing? Because you get what you pay for.

Fees Are Not the Enemy of Investors

The people who have done the best have paid high fees and commissions.

Last week, we talked about how paying fees on your mutual funds can actually help you in the longer term. Paying them on stocks can help you in the short term.

In both cases, you lose the temptation to make an infinite number of trades. You might miss a good trade, but you'll also avoid a bunch of bad ones.

I would guess that a lot of the Robinhood traders are not doing well. At least some are overtrading and chopping themselves to bits. I don't want to see that happen to you.

Sure, you see their screenshots when they are making money. But the truth is, many are probably hurting. They're not going to tell you that.

How They (and You) Can Beat the Street

Remember Ocean's Thirteen? George Clooney and his gang rigged the games in Al Pacino's (Willy Bank) casino so that customers would make lots of money.

The key, of course, is to get them to leave the casino.

In Vegas and on Wall Street, people stay and ultimately end up losing their winnings. The more bets you make, the more chances THEY have to make money. That's why they don't even need to charge you commissions.

If you play the expectation game long enough, you're going to end up with nothing. So you change the game by buying and holding.

• If you go shopping for mutual funds, get some expensive ones with loads and sales charges where it costs you 3% to get in. You'll be in them forever… and compounding your returns the whole time.

• If you go shopping for stocks, I encourage you to go with a full-service broker. Pay the high fees and commissions; those will discourage you from trading and encourage long holding periods.

And if you're wondering what to put in these accounts, I recommend that you follow my Awesome Portfolio roadmap. You can have stocks, bonds, gold, cash, and real estate and be fully invested for the long term.

I like to think of it as the financial equivalent of the Hippocratic Oath. Do no harm, and you won't lose money. And read this report to see how you can start making money today.

Jared Dillian