Some people give up too easily. They hit even a small road bump, and they just don't go on. Yet others keep trying too hard and too long, way beyond the time when quitting makes more sense. When it comes to being a successful entrepreneur or small business owner, the trick is to know your sweet spot, the place when it makes the most sense to quit or when to keep on plugging away.

It would be great if there was an app to tell when to keep working on something and when to simply accept that you failed and let go. No such luck (but it's a good bet that someone is working on one).

Every experience is different and each situation is unique. There's no measurement device for persistence or clear-cut guidelines to let you know when to give up or push through. You must know your own "Rubicon," defined as the point when "to take a decisive, irrevocable step." You have to find your own point of "no return."

Related: This Is What It Means to Embrace Failure

Don't give up (well, most of the time).

Sometimes it's a good idea to stop. Sometimes not. The choice is up to you. But, here are a few questions I ask myself when I am making the decision to go on or not:

  • Is my heart still in it?
  • Can I achieve greater results by simply moving on to something else?
  • Knowing what I know now, would I start this task today?

A friend told me about the physical therapy sessions she had a while ago, after she was recovering from a broken leg. The therapy often made her ache. But she kept on going, because she wanted to get back to her normal routine. The advice that the therapist told her stuck with me, "If it’s just uncomfortable, it's a good idea to keep going. But if it’s painful, you should stop."

The decision to continue in any business situation is much the same. If you're going hard and too fast, it may cause temporary discomfort or even a minor setback. But, if you're doing something wrong or injurious to you or your business, it's time to stop. It all comes down to risk versus reward.

Related: The 4 Factors to Making the Best Decisions for You

When your money and reputation are on the line.

It's hard to be rational about giving up when you have "skin in the game." This phrase, attributed to renowned billionaire investor Warren Buffett, refers to a situation in which insiders use their own money to buy stock in the company they are running. It also holds true to entrepreneurs who've laid out their own savings to get their business going.

Small business owners, including the many I've worked with, when confronted with adverse situations and concerns have a much higher level of commitment to their venture when their savings and good name are at stake. They'll stick to it, no matter what (even when everyone tells them to let go). Personally, I think it's that kind of doggedness that makes them successful...especially when persistence usually pays off.

Persistence and overcoming fears.

The decision to continue doing something or to stop is part of life. That’s what makes every choice interesting. In certain situations, you’ll want to use all the motivation, willpower and courage you can muster to keep going, even faced with resistance, doubt, criticism or discouraging feedback.

Persistence stands in the face of deeply-rooted beliefs and social convention. Often it’s much easier to stop than to face our most common fear of: failure or rejection, missing out, making the wrong decision, not doing something correctly, not have what it takes, vulnerability and exposure, looking silly or stupid, or even fear of success. Instead of quitting because of your fears, maybe you should persist in an effort to conquer your fears and overcome negative beliefs.

5 habits that keep persistent people going.

Sure, overcoming fears is a good start. But even more important to persistence are the habits that persistent people have in common that keep them going long and continue to motivate them after most people give up:

1. An ingrained sense of purpose. When I was starting my marketing business, this vision was the first thing I thought of when I woke up and last thing before I went to bed. It was the focal point of my life. I was willing to devote a major portion of my energies and time toward reaching it.

2. Wanting something really bad. I wanted to succeed and never looked for an excuse or a way out. This powerful desire keeps persistent people going even through tough times, repeated failures, dead ends and when it seems you're not making progress.

3. Self-confidence. A highly developed sense of self-worth allows the highly persistent to continue on without being greatly affected by what others think.

4. Disciplined habits. Small setbacks don't matter. Persistent people believe in what they're doing and that everything they do will count toward their desired outcome in the end.

5. Ability to adjust as needed. These people constantly look for better ways to increase their chances of success. They are not tied into their ego and are quickly willing to admit when something is not working and adapt to ideas that work better.

Admitting failure and moving on.

There are situations when you need the strength, humility and insight to let go and move on. I know first-hand that giving up is brutally hard. But, everyone fails at one time or another. The bigger issue is learning to cope with failure.

It's easier to give up when you admit that it's not about being brave or weak. It's about being honest with yourself. Failure comes with new opportunities and lessons.

For example, a few months ago, I read that Target is closing its Canadian stores and moving on after a bungled launch in Canada. Management realized that trying to save its operations there would require several years, tons of lost profits and a damaged reputation. So it cut its losses short, and wrote off the cost of the expansion. The company had the guts to admit defeat and dealt with it. Stockholders and U.S. customers appreciated the honest solution.

It all comes down to choices. Stop or keep going? Regardless of the choice, in the larger scheme of things, the outcome doesn’t matter as long as you continue to be honest and . That’s the ultimate success.

Related: The Importance of Staying True to Your Roots as an Entrepreneur