The rising popularity of Amazon’s Echo device family is showing no signs of slowing down; the Echo Dot was, after all, the retailer’s best-selling product over the holiday season. But have you ever wondered who builds all those skills—the name for voice-controlled apps—and how much they’re paid?

An extensive report from CNET’s Ben Fox Rubin shines a light on the indie developers and marketers who create the skills for the Echo line and other AI-powered smart speakers like Google Home.

As the Alexa economy is still in its early stages, and the fact Amazon doesn’t let most devs charge for their creations or include ads, many developers earn little for their work and consider themselves hobbyist who have day jobs.

Darian Johnson, for example, gets nothing but $100 per month from Amazon to cover his server costs, but he’s still happy to make new skills. Others, such as IBM senior developer Joseph "Jo" Jaquinta, aren’t as pleased about working for comparatively little pay. After initially receiving $5000 in one month through Amazon’s rewards program, recent months have seen that impressive amount halfed despite more customers using his skills. As a result, he is now planning to cut back on his Alexa work.

There are some success stories. Joel Wilson started developing Alexa skills in January. After Amazon initially started sending him $2000 per month, he’s received a $9000 cheque over each of the last three months. But his situation appears to be a rarity.

If you’re looking to make serious money through making Alexa skills, it seems the best option right now is to work for a marketing company. They charge anything between $10,000 and $200,000 to create skills for big-name brands like Nestle.

Amazon is offering new ways for developers to make money from their skills. In-skill purchases is a recent addition, as is the ability to include Amazon Pay in skills, letting users pay for services and goods through Alexa.

There are now 25,000 Alexa skills available in a market expected to be worth $50 million next year. While that pales in comparison to the $50 billion smartphone market, it’s growing at a much faster pace than its mobile counterpart and is worth $45.5 million more than what it was in 2015. As it grows, perhaps Amazon will be more willing to pay developers extra for their work.