Ever wonder about the ubiquity of offers to try out a service for free for 30 days? Why does the local gym not offer two weeks’ free membership?

The question bears particular relevance at a time when Americans, by long tradition, make New Year’s resolutions.

I believe the answer lies in a behavioral economic insight that savvy marketers employ to overcome resistance to the adoption of their products—namely, that when you’ve adopted a behavior for a period of 30 days, you have a greater likelihood of continuing that behavior.

Marketers have plenty of tricks up their sleeves. Why, for example, is a free sample workout not sufficient to keep you a member of a gym?

The free sample—say, for a cup of coffee or a chocolate—may be based on the principle of reciprocity or may be intended to break down resistance to trying something new or different from the customer’s usual choices.

Those cases are distinguishable from the case of a gym because there, you are being asked to do something that is, essentially, painful. For that, you need a greater degree of encouragement.

I suspect that dieting is harder still than a new exercise regimen. One can start to appreciate the benefits of exercise within days, and one can get used to the pain within a month. But if you diet successfully in January but family birthdays in February or March put a greater than usual quantity of cake in front of you, you can blow all your progress quickly and get discouraged. For a diet, a person probably needs to maintain discipline throughout a calendar year, including Thanksgiving and Christmas dinners (or the latkes and jelly donuts that challenge Chanukah celebrants).

And that brings us to the business of financial advice. I believe that for most Americans a financial workout is probably much more painful than pumping iron at the gym and at least as challenging as a diet.

Indeed, investing essentially requires the ability to defer gratification, which is a rare personality trait to start with. One has to learn—though coaching and hard experience—of the reward that comes from not utilizing a readily available income source for something wanted today so that it will be available to purchase a home, college education or retirement security in the distant future.

Because it takes from between five and 10 years to really see the cumulative benefits of this kind of behavior, and because financial markets are so volatile, a financial advisor who can serve as a support system is often critical to that success.

For that reason, the start of the year is a most auspicious time to offer prospective clients an 1,825-day (5 years) special, and for those with greater need for support, a 3,650-day special.

New Year’s resolutions are known to be by and large a flop—with research indicating something like an 88% failure rate.

But the impetus—the desire for self-improvement—is a noble one. Advisors should step in now to offer needed support for one of life’s most crucial goals. An offer of 1,825 days—or more as needed—of hand-holding would be a beautiful way to wish your prospects not only a happy 2015 but a happy 2016, 2017, 2018 and 2019 as well. You can call such a financial plan “2020 Vision.”