[atlas] Cannot understand the daily limit

RIPE Atlas just denied me a measurement: "{"error":{"status":400,"code":104,"detail":"Executing this measurement request would violate your maximum daily spending limit of 1000000 credits. Please stop some of your currently running measurements and try again.","title":""}}" I have one permanent measurement, which takes, according to <https://atlas.ripe.net/user/credits/>, 3400 credits/hour (81600/day). Otherwise, I ran only one-off measurements, most taking < 1000 credits. How could I hit a limit of ONE MILLION per day?