Shopify (SHOP -0.59%) has had an impressive run in its short life to date as a public company. Investors are cheering the market-thumping sales gains that the e-commerce platform has seen, and they're warming up to the idea that sustainable profitability isn't far away.

That lack of positive net income is one reason why Shopify might not be the best choice as a growth stock today. A few better options, according to Motley Fool investors, are Winnebago (WGO -2.15%)Canopy Growth Corp (WEED -1.78%) and TPI Composites (TPIC -8.89%).

Road trip toward profits

Demitri Kalogeropoulos (Winnebago): Winnebago is one of those rare companies that can claim faster sales growth than Shopify right now. Revenue spiked 83% in the recreational-vehicle specialist's last quarterly outing compared to Shopify's 72%.

A Winnebago recreational vehicle.

Image source: Winnebago.

Sure, the increase was mainly due to a big acquisition that added the Grand Design RV franchise to the portfolio. But it's impressive growth nonetheless, and it represents just one highlight of Winnebago's broadly improving operating results. Profitability is rising, too, as the company's sales mix shifts more toward high-margin towable vehicles. And unlike Shopify, the RV specialist is consistently producing net profits today.

Thanks to strong backlog figures, Winnebago is predicting healthy industry trends in 2018 that should power its ninth consecutive year of revenue growth. Those gains will help management make strides toward paying off the debt they took on for the Grand Design purchase.

At the same time, Winnebago will be making significant investments in expanding production and developing the next round of product releases. Assuming things go roughly according to plan, Winnebago shareholders should continue to reap positive returns as the company extracts value from its new status as a full-line RV manufacturer with growing economies of scale.

A marijuana stock that's unlikely to cool down anytime soon

Neha Chamaria (Canopy Growth Corp): Shopify is growing at a torrid pace, but there's another stock from another hot industry that's risen nearly as much as Shopify in 2017, but is growing its revenue at an even faster clip: marijuana giant Canopy Growth. Just how fast, you may ask? Well, Canopy's annual sales have soared 2,000% between 2015 and 2017.

A commercial marijuana greenhouse farm.

Image source: Getty Images.

With 29 states legalizing medical cannabis and several in favor of legalizing recreational marijuana, Canopy isn't the kind-of investment that'll go up in smoke. The Canada-based company is the largest pure play in the marijuana industry, has expanded its operations internationally into markets such as Europe, Australia, and South America, has 250,000 registered patients, and stands to be among the biggest beneficiaries if Canada legalizes recreational cannabis next year.

Canopy's biggest stamp of approval came a couple of months ago when it struck a partnership with beer giant Constellation Brands, which, as Canopy's CEO Bruce Linton recently discussed during an exclusive interview with The Motley Fool, could open up a lot of new opportunities for not just the company, but the marijuana industry overall.

Canopy is currently expanding its production capacity at a rapid pace while bolstering growth via acquisitions to ensure it remains at the forefront as competition in the industry intensifies. But given the massive opportunity that lies ahead as more and more markets open up to marijuana, there's enough room for Canopy to grow alongside, and even lead, rivals. As Canopy's sales boom, so should its stock price.

Revenue growth is great, profits growth is better

Rich Smith (TPI Composites): With sales up 74% over the past 12 months, Shopify undeniably is a great growth stock -- if what you're aiming to grow is revenues. The problem is, for-profit corporations are also supposed to (in theory) earn profits on their revenues. Shopify doesn't, and according to analysts polled by S&P Global Market Intelligence, it doesn't have even a chance of growing profitably before 2020, at the earliest.

That's why, if you ask me to name a better growth stock than Shopify, my vote goes to TPI Composites -- which I also own.

Because TPI flies below Wall Street's radar for the most part, you won't find many accurate five-year forecasts for the company's growth rate. But over the past three years, the stock has grown its revenues at a 45% compounded rate -- and its pre-tax profits at 115%. Over the next three years, analysts forecast a total 72% increase in sales, and a 70% increase in per-share GAAP profits. That may not be as fast as Shopify is growing, but it's profitable growth -- the kind I prefer.

Final point: Up until this week, a lot of investors were worrying that tax reform via an anti-alternative-energy Republican Congress would kill TPI's profits going forward. Turns out, that's not the case. When all was said and done, Congress preserved the federal Production Tax Credit for wind energy at its existing levels and added a big reduction in the corporate income tax for good measure. This leaves the road ahead clear for TPI to continue growing revenues and profits for years to come.