Here's the thing nobody tells you: an AI has no memory, so to keep a conversation going, your app re-sends the ENTIRE chat every single turn. That means turn 10 pays for turns 1–9 all over again. Watch the snowball roll.
Press Send next message. Each turn, the AI re-reads everything said so far (that's the growing bill) and adds a reply. Watch the per-turn cost climb even though your messages stay small.
💸 Cost of each turn (re-sending everything so far):
Two people get the same help. One dribbles it out over 10 tiny back-and-forth turns; the other asks one clear question. Compare the bills!
Goal: get help planning a party. You have a $0.02 budget. Choose a strategy and see if you come in under budget. Find the cheapest way that still works — solve it to win!
Budget: $0.02 · best so far: —Every serious AI app fights the snowball. Here's the toolkit, cheap trick to pro move:
Send the full history each turn. ✅ Simple, never forgets. ⚠️ Cost explodes as chats get long.
Compress old messages into a short recap. ✅ Big savings. ⚠️ Loses fine detail.
Reuse the unchanged start of the prompt at a discount. ✅ Cheaper & faster. ⚠️ Only helps repeated prefixes.
You saw the snowball: because the AI is stateless, every turn re-sends the whole chat, so long conversations get expensive fast. Now you know why pros summarize, trim, and cache — and why one clear message often beats ten chatty ones.