Have you ever quit a job, fired a customer or otherwise ended a business relationship because of a toxic person, insufficient pay or simply because you're completely bored? 

Walking away from available business or work in a questionable economy certainly means taking on some risk. But it can also be the path to great wealth. That's the lesson that emerged when financial planner Tom Corley interviewed 233 millionaires over five years, many of them entrepreneurs. 

But whether they'd earned their wealth in their own companies or in someone else's they all had one thing in common, he writes in a piece for CNBC.com: They quit their jobs mid-career or even late in their careers when those jobs became frustrating, boring or failed to provide for their financial needs. 

Many of them used a bad job situation as an impetus to strike out on their own, using what they'd learned to build successful new companies. 

The message from Corley's research is clear: If you spend your days on work that isn't really worth your creativity, effort or time, leaving that situation might well be your first step toward greater success and a much bigger bank account. 

That message really resonates for me, because in my own business, every time I've fired a client for one of these reasons, I've wound up increasing my income in the long run. 

It reminds me of something one of the smartest entrepreneurs I've known often said: The things you say no to make an even bigger difference to your success than the things you say yes to. Here's a closer look at some of the reasons Corley's interview subjects moved on.

1. Non-challenging work

Many of Corley's interview subjects felt like they were doing "zombie work," he writes – boring, repetitive, easy work that didn't take full advantage of their talents and capabilities. 

Even when you have your own company, you may find yourself doing zombie work for one reason or another – especially if you have a small company where you need to do many different jobs. And no matter what your work is, some aspects of it are bound to be uninspiring.

But if you're spending a large portion of your time on work that bores you, it's time to consider making a change, because the truth is spending most of your time on that kind of work rarely leads to huge success or great wealth. 

That may mean hiring someone, or several someones, to take over mundane tasks. It might mean pushing yourself to go after more challenging and interesting opportunities or expanding into new markets.

We spend a great deal of our time, energy and focus on whatever we do for work. That work should come as close as possible to using our full capabilities.

2. Toxic people

Some people are just hard to get along with. But if you're stuck dealing with a toxic person in your work life, it can hold you back from achieving real wealth. That's because all of us, employees and especially entrepreneurs, need the help and support of the people we work with to advance our careers. 

And someone who's truly toxic (as opposed to just crabby) probably isn't thinking about what's best for you or how to help you.

It's highly likely that getting away from someone like that will likely help you be more successful. So do what you have to: Find someone different to deal with, gently fire the customer or try some strategies to make them less toxic, at least where you're concerned.

3. Not making enough money

If you're otherwise happy with your current business or job, but you're not earning quite enough, it can be tempting to stick with what you know and try to cut expenses to make the economics work.

But if you want wealth, you need an employer who's willing and able to pay you what you're worth – and that's especially true if your employer is you.

During the earliest stages of starting your business, you may need to pay yourself a very small salary – or even no salary – in order to be what Paul Graham calls "ramen profitable". But if you've been at it for a couple of years or longer and you're still not making a living that works for you, you know it's time to make some changes.

In my new book Career Self-Care, I offer readers guidance to help figure out why they might be unsatisfied with their current work. And I offer some specific strategies for growing your career and for building the skills and relationships that will help you get where you want to go. 

The important point is that if you're in a situation where you are unchallenged, underpaid, or have to put up with toxic behavior – don't just grit your teeth and bear it. There's almost always something you can do to make it better, whether or not you actually fire a client, leave a job or make other major changes. 

If you do decide to make a major change, that can be scary. But it might help to know there's a healthy chance you'll wind up richer for having left. 

Inc