Love him or hate him, Donald Trump is the master of dominating the 24-hour news cycle. Whether you think he will “Make America Great Again” or that he’s a clown, a closet leftist or Adolf Hitler reincarnate, he certainly has a habit of getting his face on the television screen.

And, of course, this master marketer is now the presumptive Republican nominee for president. Leaving politics aside as much as possible, let’s look at what aspiring entrepreneurs can learn from the Donald — both the good and the bad.

The Good

Machiavelli said it was better for a prince to be feared than loved. At the very least, Donald Trump has made it clear that it’s better to be loved and hated than not cared about at all. After all, you can win an election even if 49 percent of the country hates your guts.

No one punches back quite like The Donald (or takes offense quite as easily), and he rarely uses nuance or subtly when making an argument. Now, this quality is not good in and of itself. Indeed, it doesn’t even seem like he acts like this in his daily business, as many of his current and former employees have very good things to say about him.

However, if it needs stating — no, it is not a good idea to be so hostile with employees, vendors, potential sellers, partners and the like.

But what it does mean is that you shouldn’t be afraid to be a little controversial. And much of Donald Trump’s marketing success comes down to his ability to be controversial, even when he wasn’t running for president. Successful people are being criticized almost all the time and the same will happen to you. This isn’t something to fear, indeed, it’s a sign of success.

There’s an old saying in real estate investment that if you’re not embarrassed by your first offer, you’re offering too much. This flows in the same vein as being controversial so to speak. There’s a negotiating lesson called “collecting no’s” where you are supposed to go around asking people for things you know they will say no to just so that word no longer stirs up any fear. Some salespeople even count “no’s” as a success because they get one yes for every X no’s. “Four more no’s and I’ve got another sale” or something along those lines.

(On an aside, this might be what Trump is doing regarding his plan for immigration. Make a high ball offer—i.e. build a wall and suspend Muslim immigration—in order to “meet in the middle.” But that’s aside the point.)

So someone may get upset with you after making a low offer. The person may get upset with you as well. But the next one might say yes. And it’s better to get one good deal after sifting through a bunch of no’s, even somewhat angry no’s, than to either settle for a bad deal or just sit around twiddling your thumbs and hoping no one will notice you.

The same goes for other relationships throughout business. In The Art of the Deal, Trump notes that he still finds it worth his time to pick up the phone and call a contractor if he feels he’s being overcharged even by $10,000. (That’s a small sum for him, folks.) Letting things just slide often just lets the issue get worse.

Sometimes employees, vendors and the like need be disciplined or at least know that they aren’t meeting your expectations. Sometimes you need to negotiate or renegotiate with them. And sometimes, when you can’t come to terms, you need to be willing to walk away or fire someone.

This kind of thing is not going to make you popular with everyone. Part of business and leadership is being unpopular sometimes. Sure, you want to treat everyone fairly and build a strong team atmosphere, but playing nice to get along will just allow mediocrity to fester.

The Bad

I vaguely remember hearing once that Trump mentioned early in his life that he wanted to be a movie star. I can’t find a reference to that, but it wouldn’t surprise me. Especially given that he turned himself into a reality TV star on The Apprentice before turning to politics; which is, as they say, show business for ugly people.

(Correction: Donald Trump is incredibly handsome. AMAZING!)

Either way, it seems that Trump has a hard time sitting still. It’s hard for him to stick with a winner. Instead, he has let his marketing side/show business/brand name go wherever it possibly can so that we don’t just have Trump Tower, Trump Palace and Trump Ties, but we also have a whole host of failed businesses that no longer exist, such as:

• Trump Airlines
• Trump Vodka
• Trump Magazine
• Trump Steaks
• Trump: The Game
• GoTrump.com

His casinos also had to file for bankruptcy. And I don’t think I have to tell you how Trump Mortgage, which he started in April of 2006, turned out either.

According to Forbes, after taking a $1 million loan from his father in 1968, Trump had built his real estate empire up to a net worth of $500 million by 1982. Today, Forbes claims Trump is worth $4.1 billion. Trump himself claims he’s worth closer to $10 billion. Either way, had he just sold out in 1982 and invested that $500 million in the S&P 500, he would be worth around $20 billion today.

Trump seems to have fallen for the “shiny object temptation.” He drifted further and further away from his core competency with which he had made such a fortune and suffered as a result. Of course that doesn’t mean that one has to be dogmatically focused on only one thing. Perhaps an opportunity comes along that’s simply too good to be true. But it should have to meet a very high threshold in order to justify deviating from your business and strategy.  It’s simply extremely hard to master something. And it’s extremely hard times two to master two things. Donald Trump became the master of real estate development, then devolved into the jack of airlines, ties, bottled water, steaks, magazines, mortgages, reality TV shows, and just about everything else.

Of course, just because Donald Trump couldn’t match the returns of the S&P 500 over the last 30 years, doesn’t mean he’s a bad businessman. Those are some of the best businesses in the country. But what it does imply strongly is that by dabbling around in so many different industries instead of focusing on his strength, Trump left a ton of money on the table.

I’ll leave it to the reader to determine whether his presidential campaign is simply another unwarranted deviation.