So far the stock market has had a pretty good year, with the S&P 500 up over 6% while the NASDAQ has jumped 12%. But please, don't take this as a sign that you've missed the boat.

While there's no telling where the stock market will head over the short run, there's one undeniable fact that can never be repeated enough: over the long run, the stock market is the greatest wealth creator the world has ever seen.

Money flying out of a briefcase.

Image source: Getty Images

Today, I'm going to share five consumer service stocks that I believe could help create such wealth. And my money is firmly where my mouth is: I own all five stocks. Each of these companies has two or three very powerful forces that make them worthy of your investment dollars.

Company

What it Does

Amazon (NASDAQ:AMZN)

Global e-commerce juggernaut

Priceline (NASDAQ:PCLN)

Leading hotel and airline booking site

Ctrip.com (NASDAQ:CTRP)

Same as Priceline, but focused primarily on China

Mercadolibre (NASDAQ:MELI)

E-commerce and payment specialist for Latin America

Bitauto (NYSE:BITA)

Chinese site for buying, selling, financing cars

The strength of a moat

By far the most important thing to investigate in any stock purchase is the sustainable competitive advantage -- or "moat" -- that the underlying company has. Over the long run, a wide moat is what keeps customers coming back for more, year after year, while keeping the competition at bay.

All five of these companies benefit from one of the strongest moats imaginable: the network effect. With each new customer that joins the site, a vendor has added incentive to join the platform. And with each new vendor that joins the platform, potential customers have added incentive to visit the site. It's a virtuous cycle that creates massive wealth.

Amazon's third-party sales are booming thanks to the fact that many smaller businesses realize that it's beneficial to use the company's fulfillment services and list their products on Amazon. Mercadolibre is in the same boat -- it literally creates the market for selling goods in Latin America.

Priceline owns Booking.com, one of the most popular sites in Europe for finding hotels. Ctrip has followed in Priceline's footsteps to create a "one-stop shop" for any Chinese citizen's travel needs, including planes, trains, buses, hotels, and packaged trips.

And while Bitauto might be a lesser-known name, the company has attracted investments from some of China's biggest names as it becomes a leading platform to advertise, buy, and sell cars on the Internet.

Optionality creates multiple futures

We need to accept the fact that we can't predict the future. As such, it's impossible to know how a company's current line of business will perform in the future. One way to hedge against unexpected troubles is to invest in companies that embrace multiple futures.

Another way of saying this is that we should be investing in companies that have shown an ability to adapt and evolve over time. They tinker with low-risk experiments: if those experiments fail, they have the option to kill them. If they succeed, they have the option to continue following them. The key is that losses are limited, while gains have no cap.

Amazon is the poster child for optionality: starting as a book store, adding an e-reader, expanding to far more than just books, offering free shipping for an annual fee, paying for original content, and even becoming a cloud king.

But Amazon's not alone: Priceline owns OpenTable, a restaurant booking app. Ctrip's foray into trains and buses is still in its infancy, Mercadolibre's MercadoPago is becoming a huge source of revenue as a payment option, and Bitauto has found new life by offering to connect car dealers with financiers who are willing to loan money for payments.

The bottom line is that none of these five is locked into a single line of business, and all have the potential to -- through trial and error -- stumble upon another huge opportunity.

Skin in the game

Finally, I almost always look for companies where management has lots of skin in the game via stock holdings. Even more so, I'm constantly on the lookout for founder-led companies, as founders have existential motivation to make something that is both lasting and powerful.

Alas, Priceline doesn't fit this bill, as its founders are long gone and management currently owns less than 1% of shares outstanding. But the rest of these companies have management with lots of skin in the game.

Company

Founder

Role

Percent of Shares Owned by Management

Amazon

Jeff Bezos

CEO & Chairman

17%

Ctrip

James Liang

Chairman

4.1%

Mercadolibre

Marcos Galerpin

CEO & Chairman

9.7%

Bitauto

William Bin Li

CEO & Chairman

17%

Data source: Most recent DEF 14-A or 20-F Filings for each company.

By investing with these companies, you are putting your money in the hands of folks who have the exact same incentives -- long-term value creations -- that you should be hoping for.

Taken together, these five account for 32% of my real-life stock holdings. The combination of a wide moat, optionality, and skin in the game gives me confidence that they will continue to be long term winners, and the conviction to say that they are worth buying in 2017.

Brian Stoffel owns shares of Amazon, Bitauto Holdings, Bitauto Holdings, Ctrip.com International, MercadoLibre, and Priceline Group. The Motley Fool owns shares of and recommends Amazon, MercadoLibre, and Priceline Group. The Motley Fool recommends Ctrip.com International. The Motley Fool has a disclosure policy.