Prompts may well be the new oil. Writing the text strings that instruct AI systems like ChatGPT and DALL-E 2 to generate essays, articles, images and more has become a veritable profession, commanding salaries well into the six-figure range. Anyone can come up with prompts, of course. But only certain prompts (e.g. "Create a watercolor of a solider standing in the middle of a field, in the style of John Singer Sargent) accomplish very specific, desirable (or undesirable) things. Prompt writing requires skill and dedication, owing to the black box and unpredictable nature of today's bleeding-edge AI systems. Complicating matters further, the systems are frequently changing and responding to malicious prompts, bypassing the guardrails that their makers put in place. But not every company or developer has the budget to hire a so-called prompt engineer. Prompt marketplaces, or e-commerce portals where users can buy, sell or give away prompts "designed" for various AI systems, are a growing industry. When we first profiled prompt marketplaces last July, there was only one major player. But since then, the landscape has expanded dramatically. Even a cursory Google search turns up a dozen or more prompt marketplaces, with new ones added on a monthly basis. ChatX, for instance, offers prompts tuned to ChatGPT as well as popular image-generating systems like DALL-E 2, Midjourney and Stable Diffusion. NeutronField's prompts for sale cover a slightly wider range of AI systems, including Disco Diffusion and Craiyon. Many of the marketplace operators, like NeutronField's Miroslav Kostic, have no background in AI or even data science. They were hobbyists to start, experimenting with systems like Stable Diffusion but running into hurdles unlocking their full potential. "I've been playing with AI text-to-image models since Disco Diffusion first appeared in September 2021," Kostic told TechCrunch in an email interview. "I spent countless hours trying to bring to life the ideas that had been in my head for years -- dystopian sci-fi landscapes and otherworldly spacescapes.