Selling custom GPTs, AI agents and agent tools

The claim

“This made me quit my 9-5 job for GOOD. CUSTOM GPT’S. You can make THOUSANDS selling them, and the best part is literally anyone can learn it. Like + reply ‘GPT’ and I will DM you the full guide!”

@Zephyr_hg, 25 November 2024, 38,145 views¹

A custom GPT is a version of ChatGPT set up for one job without writing code. An AI agent is a program built on an AI model that carries out a task in steps. The same pitch is made for agents and for tools agents pay to use. This page judges the scheme, not the people who tweeted.

The sums

Custom GPTs. OpenAI’s help page says personal accounts “cannot create or publish new GPTs”². It adds: “Custom GPTs are scheduled to retire on Dec 11, 2026.”³ OpenAI says the dates may change³. A GPT sold to a client stops working on that date unless it is rebuilt³. The replacement, called plugins, may not sell digital products or services inside ChatGPT for now¹⁹. The tweet dates from late 2024, before any of this¹. OpenAI said in 2024 it would pay US builders. Only a small invited test followed, and we found no published rate or figure for what that group was paid⁵⁶.

Tools paid per run. Apify is a store where developers publish small programs and users pay to run them²⁵. AI agents can pay there without an account²⁷. The developer gets 80% of the fees, minus running costs²⁵. A $1,000 monthly payout needs more than $1,250 of charges to users (our sum)²⁵.

Building for clients. One freelancer’s GPT listing asks $40 to $250 a job¹⁷. To reach $1,000 a month takes 25 jobs at $40, or 4 jobs at $250 (our sums)¹⁷. Of 43 established firms in the partner directory of n8n, an automation tool, 42 say they accept no project under $1,000, while the average bid on one open job board was $102⁷⁵.

What happens to most people who try

In our download of Apify’s public data (63,617 of about 83,000 listings), the median (middle) paid listing had 1 user in 30 days, and about 92% had 10 or fewer³⁰. Counted per developer, the median was 5 users in 30 days, and the top 10% of developers had about 95% of the users counted (our count)³⁰. A user count is not income and may include a developer’s own test runs³⁰.

Custom GPTs showed the same shape. One study of about 334,000 GPTs in early 2024 found 28.5% had more than 10 conversations⁸. We found no checked income report from any GPT seller.

The upside

Apify says: “$1.6M paid out last month. Many developers earn over $3k.”²⁸ These are its own figures, not audited, and it publishes no median²⁸. Its stated payouts rose from $563k in September 2025; we did not find how fast the number of developers grew²⁸⁷².

If payouts follow user counts, an untested assumption, $1,000 a month goes with about 450 users in 30 days (our estimate)²⁸³⁰. About 200 developers, about 6%, had that many (our count)³⁰.

Best cases:

• Advanced GSC MCP, a paid tool for AI agents, shows “$4,632/month in verified Stripe revenue” on a site that reads sellers’ payment accounts³⁴. That is revenue, not profit, and we read the page through a summarising tool³⁴. We found 8 listings on that site with “mcp” in the name; this was the only one above $1,000 a month, and the sample is tiny³⁵.
• TaxWorld, an Irish tax-law assistant, reached €1 million a year with 740 paying customers, its platform’s vendor says⁴⁶. Not checked, and not a GPT Store product⁴⁶.

What it takes to compete

• Programming skill. The most-used Apify tools are scrapers: programs that collect data from large websites³⁰. A tool left broken for 30 days can be removed²⁵. Many sites’ terms forbid scraping, and whoever publishes the tool is responsible for obeying them²⁵⁷⁴.
• Many tools. More tools go with more users: developers with one paid tool had a median of 1 user in 30 days; those with more than 40 had 227³⁰.
• Time. Writing for an Apify programme, one developer said he worked “15 to 20 hours per week” for six months to reach 98 tools, and declined to give his revenue⁷¹.
• For client work, selling. A founder selling agents to manufacturers found the second and third customers “way harder than we expected”⁴⁵.

Money costs are small: tool subscriptions of tens of dollars or euros a month, plus any AI model fees²³²⁵⁶⁶. The real cost is unpaid time: Apify’s documents say to reserve “approximately 2 hours per week” for fixes and support⁷¹.

How to tell early: check your user count after a month. A few dozen real paying users in the first months is already the top tenth³⁰. If you cannot program, the tool stores are closed to you for now. What remains is client work, or packaging expertise you already own, as TaxWorld did⁴⁶.

Who else makes money from it

Apify keeps 20% of what users pay and bills the running costs²⁴²⁵.

The @Zephyr_hg profile now links to a free daily email newsletter; the same site offers a paid community about working with the Claude AI assistant, at $147 a month for the first members. Neither page mentions custom GPTs or makes an income claim⁵⁰⁵¹.