A few weeks ago, I got an invitation to attend a free presentation, lunch included. Now, I love free lunches, and I'm a curious sort, so off I went. (It didn't hurt that the invitation promised to tell me how to make a lot of money online.)

The presentation was slick and persuasive. My cynicism served me well, but all around me, I could sense that other attendees were getting excited. We were shown photos on a screen of happy people who'd turned their lives around thanks to this company's products and services. They were raking in thousands of dollars per month -- often tens of thousands. And best of all, they weren't rocket scientists. No brain surgery was involved. These were laid-off truckers and single moms who were able to make big bucks.

We were soon invited to an all-day seminar a week or two later, which would only cost us a pittance to attend. (And again, lunch included!) Since the cost wasn't much more than the price of that lunch, and I remained curious, I signed up. This time, a large hotel meeting room was crammed with people. It soon became clear that our road to financial salvation would initially cost us several thousand dollars. The presentations were getting boring and repetitive, too, so I ended up leaving -- sadly, before lunch even arrived.

Overdue diligence
Upon leaving, I did what I should have done a lot earlier: searched for the company's name online. Lo and behold, I found a mention of a lawsuit. And then another! In one story, the company had agreed to pay back hundreds of thousands of dollars to attendees of some seminars. In other stories, various states had taken actions to stop the company from operating there. I read alleged testimonies from customers who didn't get the service they'd expected. In other words, the once-intriguing financial opportunity suddenly lost its shine.

I wish I'd done this digging earlier, so that I could have either skipped the seminar, or warned some of the other sheep I saw in attendance.

What to do
I'm telling this story in the hope that you'll also be cynical if confronted with a get-rich-quick opportunity. Getting rich usually takes some time, but it can be done. One way is via simple mutual funds -- you plunk in some money and then wait for growth over many years. (Just choose your funds carefully.) Over time, these kinds of investments can pay off much more reliably and effectively than some get-rich-quick scheme, where the only one getting rich is usually the seminar's sponsor.

If you're looking for some top-notch mutual funds, take advantage of a free trial of our Motley Fool Champion Funds newsletter. In this month's brand-new issue, Foolish fund expert Shannon Zimmerman highlights a fund that has ridden investments in Chesapeake Energy (NYSE:CHK), Waste Management (NYSE:WMI), and Qwest (NYSE:Q) to impressive gains. I've found some other gems, myself, and the newsletter's record is darn impressive so far. A free trial will give you full access to all past issues, so that you can read about every recommendation in detail.

Longtime Fool contributor Selena Maranjian doesn't own shares of the companies mentioned in this article. For more about Selena, view her bio and her profile. Chesapeake Energy is an Inside Value recommendation. The Motley Fool is Fools writing for Fools.