The Smartmodem and its clones also aided the spread of bulletin board systems (BBSs) because it was the first low-cost modem that could answer calls. Modems had previously been typically either the call-only, acoustically coupled models used on the client side, or the much more expensive, answer-only models used on the server side. These were fine for large computer installations, but useless for the hobbiest who wanted to run a BBS but then periodically use the same telephone line to call other systems. The first hobby BBS system, CBBS, started as an experiment in ways to better use the Smartmodem.