Pricing for AI Chatbots

One big difference with generative AI is that the marginal cost of usage is pretty noticeable.

I've been thinking about building a chatbot for small businesses to put on their website, but I'm worried about having my customers' customers spam the bot and create a huge bill for me on OpenAI. Even if it isn't spam, high usage could run that bill up anyways.

I've seen a bunch of people working on AI Chatbots leveraging ChatGPT and GPT-4 here. I'm curious what the pricing models people using or thinking about using or ways people are preventing their operating costs from ballooning.