Sometimes people ask me what stocks they should invest in. Underneath this seemingly innocuous question there lies a dangerous presumption that all investors have the same goals.

The fact of the matter is that there are as many different ways to successfully invest as there are investors. The key is to first identify what you hope to accomplish.

This article is written for a very specific crowd: those who are in their 50s and will likely be retiring anywhere from 10 to 20 years from now. It's also written for those who believe that such a timeline is long enough that they shouldn't be investing only in safe, dividend-paying stocks, but rather a more balanced portfolio.

Below, I'm offering up three stocks that can help you achieve that balance: a reliable dividend-paying stock, a stable goliath that's still growing, and a smaller more growth-oriented company that's got some serious tailwinds pushing it forward.

Verizon (NYSE:VZ)
Telecom giants have a couple key advantages that every dividend-investor should love: copious amounts of free cash flow (FCF) and significant moats created by high barriers to entry. Those high barriers to entry exist because telecoms need to spend tens of billions just to lay the infrastructure necessary to compete in today's mobile-based world.

No company has done a better job at capturing that potential -- and solidifying its moat in the industry -- than Verizon. Since buying the remaining stake of Verizon Wireless from Vodafone, Verizon now owns 35% of the U.S.-based wireless market, according to Strategy Analytics.

Just as importantly, it offers a mouth-watering 4.4% dividend yield that is surprisingly safe.

As you can see, over the last three years, Verizon has never used more than 60% of its FCF to pay out its dividend -- and last year it only needed 40% of its FCF for its outsized dividend. That means that this dividend is very safe, and has lots of potential for growth over the next 10-20 years.

The company formerly known as Google is an absolute powerhouse in every sense of the word. Alphabet owns the first and third-most popular Internet sites in the world -- and -- and is able to collect gobs of information about users that it can then monetize through targeted advertising.

Those advertising dollars have been building up over time: Alphabet's current cash pile is north of $70 billion. With that kind of money, you know that Alphabet isn't going to disappear anytime soon. In fact, with so much cash on hand, I wouldn't be surprised to see the company buy back more of its stock, or starting to pay out a dividend over the next 10-20 years.

Throw in the fact that if any one of Alphabet's "moonshots" ends up hitting it big the company will be even more flush with cash, and you begin to see why I think this is a very good stock for someone in their 50s to consider owning.

Veeva Systems (NYSE:VEEV)
This is by far the smallest and most speculative of the three companies. Veeva provides cloud-based solutions for pharmaceutical companies, is valued at just over $3 billion, and trades for almost 70 times trailing earnings.

The company was founded when current CEO Peter Gassner was working at and realized that there were specific services that this sector needed, and that they could be better addressed by a company focused solely on them.

Beyond the fact that Gassner is a founder who has significant skin in the game (he owns over 20% of the company's Class B shares), there are two other things I like about this tiny company.

First, its customers (pharmaceutical companies) are loath to switch providers of such critical services. Veeva's CRM solutions have tons of data stored for the sales force of hundreds of drug companies throughout the world. Furthermore, the company's Vault solution -- which helps collect data and navigate the arduous drug approval process -- has even more mission-critical data stored on it.

Switching over from Veeva to a competitor would be a huge headache and require the retraining of thousands of employees -- not to mention the retrieval of very important and sensitive information. That, plus the fact that Veeva has been winning over customers with its Vault offering, has me very excited about the company's potential moving forward.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.