Investors can face investment obstacles on a daily basis, whether it's a change in their financial situation, deciding on where to put their money, or facing market volatility outside their control. Some obstacles can be more about overcoming the lure of shiny new devices, or the potential promise of a burgeoning market such as recreational-use marijuana. Or perhaps you avoid adding "boring" companies to your portfolio.

In this article, I've highlighted the stocks of two companies that investors might consider boring -- but the return on investment over the past 10 years would indicate otherwise.

1. Aon

According to a study in the Personality and Social Psychology Bulletin published in March, it was noted that the three most boring jobs are related to data analysis, accounting, and insurance. If that's the case, then investors may think Aon (AON -0.30%) could be a boring investment.

Aon may not be the first company an investor thinks of when it comes to financial stocks investments, but that could be an error. Its established financial and insurance services help businesses manage risk, insurance, health, and wealth. In doing so the company analyzes data, performs assessments, and provides solutions to assist with financial performance and reinsurance. 

Aon has enjoyed average annual revenue growth of 4.6% on a year-over-year basis dating back to 2018.In its most recent (second-quarter) earnings report, the company boasted a 3% growth in revenue, to $3 billion, driven by 11% organic growth from its health solutions unit, and 8% organic growth overall. The company attributes its strong growth to retaining existing customers, as well as generating net new business, which can go a long way toward future success.

Revenue growth helped boost earnings to $500 million for the quarter, and management has been able to contain operating expenses in line with the Q2 revenue growth rate, which helped lead to a 40% spike in earnings per share (EPS) year over year. If that spike in EPS doesn't grab investors' attention, a projected average annual revenue growth rate of 4.7% and an average 9% earnings growth for the next five years could do the trick.

Investor confidence has been high for quite some time. Aon's stock price has doubled over the past five years -- up 470% over the past 10 years. And in Q2, the company approved a $500 million share repurchase, following the authorization of a total $7.5 billion share repurchase program. That announcement came along with a 10% hike in the quarterly dividend for investors, which should help maintain that confidence going forward. 

Aon expects to utilize its strong cash flow to support mergers and acquisitions, and share repurchases. Growing out its health unit could allow the company to capitalize on challenges facing its clients related to rising healthcare costs. The company is also looking to expand in areas that assist its clients with unmet needs.

When challenges facing clients involve optimizing spend and services, a company like Aon could certainly be on a path to significant growth. As the company states, it's looking at mid-single-digit year-over-year growth for 2022, 2023, and beyond.

2. Waste Management

Chances are if I walk into an investment seminar and ask how many people enjoy collecting trash, I'm not going to see very many hands in the air. But if I ask how many enjoy investing in the dominant player in trash collection in North America, I'd hope to see the opposite. 

Waste Management (WM -0.49%) has been doing right for investors for years -- so much so that investor confidence has supported a stock price that has gained 400% over the past 10 years, and is up 4% year to date, while the S&P 500 is down 12%.

The company's success stems from being a well-established powerhouse providing varied environmental services, including waste collection, renewable energy, and recycling, with a lot of cash to help the business grow. Boasting a customer churn of 9%, the company keeps its customers for an average of 10 years, though the average length of a contract ranges from three to seven years, meaning many customers opt to renew contracts.

The company's vertically integrated model also helps it optimize profits -- averaging nearly 12% net margin while the competition averages 10%. 70% of its trash collection is disposed of at its own landfills, which keeps outsourcing and uncontrolled costs at a minimum.

One of the primary obstacles Waste Management faces is that of being in a very competitive market. But as competitors may be able to steal away a few contracts here and there with special pricing, ultimately, it's more difficult for the competition to build out new landfills due to regulatory requirements and local backlash. That keeps Waste Management in play for those services regardless of the collection company.

On the renewable energy front, the company has the support of a market projected to grow at a compound annual growth rate of 8% through the end of the decade, backed by a presidential administration that has made climate and clean energy a focal point.

Lastly, management has been highly successful in maintaining a strong balance sheet. As a result, the company expects to spend $300 million to $400 million in 2022 on acquisitions that should help it grow, and another $980 million in stock repurchase, which should be music to the ears of long-term investors.

Inflationary costs are being offset by higher pricing, volume is growing and expected to remain strong, and the company is giving back to investors in the way of annual dividends. The current annual dividend of $2.60 per share is at a yield of 1.45%. This represents the 15th consecutive year the company has raised its dividend, averaging a compound annual growth rate of 6%.

As humdrum as trash collection may seem on the surface, Waste Management provides quite an exciting opportunity for its investors.