It depends on how you run them. For growth, where accounts are new and post actively, plan on three to five accounts per line depending on the platform. For maintenance, where aged accounts are kept warm with light activity, one group of up to eight or ten accounts per line works, with one rotation per group switch. The calculator on the plans page turns your numbers into a line count and a cost per account. Fingerprints, schedules and behaviour matter more than the IP.