Adoption of web browsers was also much lower when Netscape was dominant. 90% marketshare is less meaningful if you're only 1% of the way to the potential market size. Peeling away users who talk to ChatGPT every day is very possible, but harder than getting someone whose never used an LLM before (but does use your OS, browser, phone...) to try yours first.

I think the even better analogy than browsers is search engines. There aren't any network effects or platform lock-in, but there is potential for a data flywheel, building a brand, and just getting users in the habit of using you. The results won't necessarily turn out the same - I think OpenAI's edge on results quality is a lot less than early Google over its competitors - but the shape of the competition is similar.

> How many of those users are paying?

About 5% according to a news article a few months ago.

Will the other 95% stick around once ads or payments are required?

They'll stay as long as it's cheap. The moment any attempt is made to raise the price, the number will crater.

for 99% of normies ChatGPT is the only LLM provider they know or have heard of.

"Anthropic" doesn't exactly roll off the tongue, and I think a lot of people would avoid it simply because it doesn't have a catchy name like OpenAI or ChatGPT. It's also far more fun to say "I did a Google search" than "I did a Duck Duck Go search", and one still dominates over the other no matter the privacy concerns or how easy it is to switch. People can be simple like that.