They deduct $3.99 every one month after not using their service for 180 days: ["A note about account maintenance fees It looks like you haven't redeemed an Ibotta offer in the past 180 days (redeeming an offer means you got cash back for an offer in the app or browser extension). Per our Terms of Use, account maintenance fees of $3.99 are deducted from your Ibotta earnings each month if you haven’t redeemed an offer in 180 consecutive days." ...] Read their maintenance fees carefully!