Co-founders Tom and David Gardner look back on The Motley Fool's journey with Amazon.com (AMZN 1.62%) since first purchasing it in September 1997. The brothers discuss the ups and downs they've seen with the stock, now a 100-bagger for the Fool.

In this video segment David Gardner discusses how he picked Amazon, and how today's investors can look for the next 100-bagger. The most important factor, he says, is the quality of the business itself -- the momentum and disruption it brings to the table.

Tom Gardner: I just want to put those three factors in the context of finding the next 100-bagger.

Maybe just give an example. You don't have to give a specific company, but what sorts of trends and themes are out there today that are bringing together the visionary leader with the broad approach -- the Amazon-like name, rather than in the narrow niche -- and the consumer experience that you have?

David Gardner: Of those three factors we talked about, if you're looking for the next 100-bagger, I think the primary factor of those three would be the second, which would be the business itself, and the momentum and the technology and the disruption.

Amazon, in a sense, is just a poster child for e-commerce. E-commerce was the real story in 1997, and it has been for the 16 years since. E-commerce has been unbelievable, and Amazon is the greatest brand and greatest example of that.

But e-commerce benefited many companies; eBay was an early pick of ours that we still have maintained. It's done very well. So, Tom, I think looking and thinking ahead of trends and asking yourself what's going to be really big, would be the best way to locate the next 100-bagger.

Tom: How about sales growth? We were talking off-camera beforehand. If you go back to -- I could only date back in the SEC filings online to 1999. It was two years after you bought.

David: For Amazon? Okay.

Tom: For Amazon. Amazon, in that single quarter, did about $350 million in sales and, in the same quarter the previous year, was $150 million in sales so, they had at least a run rate of more than $1 billion in sales, but their growth rate was north of 100% in revenue.

Is that a factor that is an indicator for you of whether there's a huge market opportunity and a big theme, is the top-line growth rate?

David: Yeah, I think it is. As a Rule Breaker, obviously, I'm never going to say "That's it and that's always it," because there's all kinds of exceptions. It's always about context. But I think that's a pretty good indicator.

When we talk about big things like e-commerce or two recent trends that we've been early on and it's been to our benefit -- 3-D printing and cloud computing -- both of those in the Rule Breakers and Stock Advisor services, we had early picks in those. Those are really big stories and they had big sales growth. It wasn't just a hope and a dream. And there are many examples of it.

It doesn't always have to be the biggest thing of all. I mean biotech in a big way -- but also small ways, like just genomics or just a given cure -- exhibits these characteristics on a more microcosmic level.

Anyway, it's not always about the next big trend, but Tom, sales growth is definitely a factor.