With earnings yields reaching record lows, it is becoming more and more difficult to find growth stocks that are not overvalued, let alone stocks with sustainable growth. Fortunately, there's still a small pool of such assets available to investors.  

Over the past year, shares of PLBY Group (NASDAQ:PLBY), Curaleaf (OTC:CURLF)(CNSX:CURA), and MercadoLibre (NASDAQ:MELI) have gone up 345.3% (from September onwards), 231%, and 175%, respectively. Let's see what they have to keep their momentum going.  

Man discussing growth strategies in a meeting.

Image source: Getty Images

1. PLBY Group (Playboy)

Playboy captivated a lot of investor attention this month after announcing it would develop its own non-fungible tokens on the ethereum blockchain. This would allow the entertainment firm to securely store the assets (such as photographs, covers, art, etc.) from its namesake magazine. It could then auction them off to collectors, with the assurance that buyers would be getting the authentic images via ties to the tokens.

Nowadays Playboy gets most of its revenue from e-commerce sales and brand licensing. It has over 1 million active digital commerce customers, as well as 50 million social media fans. The company sells gaming, lifestyle, beauty, fashion, and sexual wellness products.

Last year, its sales improved by 89% year-over-year to $147.4 million. The company's operating income simultaneously flipped from negative $6 million in 2019 to $13.6 million.

What's more, Playboy's model is highly sustainable. It has over $400 million in backlogs from royalty revenue all the way through 2029. About 95% of merchants who use Playboy's brand renew their contracts. The segment itself brought $66.6 million in sales in 2020, with a gross margin of 80%.

Playboy also acquired TLA Acquisition Corp for $25 million as a stepping stone into the adult-novelties business. The deal should deliver a fair amount of synergies considering Playboy's brand image. Given its future growth prospects, the stock is a pretty good buy at 10.5 times revenue, especially considering that management estimates its sales will reach $290 million by 2025.

2. Curaleaf

With a pro forma revenue of $767.1 million in 2020 (up 305% year-over-year), Curaleaf is currently the No. 1 cannabis operator in the U.S. It is arguably also the safest bet in the nation's $21.7 billion total addressable market for pot.

The company has 101 dispensaries across 23 states, and is the market share leader in New Jersey and Pennsylvania. It also has over 1,800 wholesale locations. Curaleaf offers vapes, oil, concentrates, dried flower, pre-rolls, topicals, capsules, tinctures, mints, lozenges, and edibles. 

The stock is well worth its price of 16.5 times revenue for all the growth it provides. The company recently entered the E.U. cannabis market (the first U.S. marijuana firm to do so) with its $286 million acquisition of EMMAC, a leading independent cannabis growing company with a target production rate of 10,000 kg of dried cannabis by 2022 (which should sell for about 70 million euros per year). At the end of the day, Curaleaf is a top choice for investors interested in cannabis stocks.

3. MercadoLibre 

MercadoLibre is currently the No. 1 e-commerce platform in Latin America. Ninety-five percent of its sales stem from just three countries: Argentina, Brazil, and Mexico. Last year, its active customers grew to a record 132.5 million from 74.2 million in 2019. Keep in mind there are only 650 million people in the entirety of Latin America.

The firm brought in $3.97 billion in revenue from $20.9 billion worth of merchandise, up from $2.296 billion in revenue and $13.997 billion in merchandise volume in 2019. What's more, it finally broke even in terms of operating income with a positive $127.7 million, compared to a loss of $153.2 million over the same period in the previous year.

What makes MercadoLibre sustainable is its dedication to logistics. Currently, Latin America does not have the infrastructure to sustain small-cap e-commerce players given their shipping needs. But MercadoLibre has the size to invest in infrastructure projects to expand its own shipping, such as opening up an airline flying between Brazil and Mexico.

Overall, its stock valuation of 20 times sales is pretty hefty, but that valuation is well justified for a company with a revenue growth rate of 72.9%. This is definitely a popular e-commerce stock not to be missed. 

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.