Some businesses find that the human touch can improve contact, thus sales, but traditional wired answering services are expensive, so they have their calls forwarded to a call center, so the client can reach an operator instead of an answering machine or voice mail. Before the availability of call forwarding, commercial answering services needed to physically connect to every line for which they provided after-hours response; this required their offices be located near the local central exchange and be fed by a huge multi-pair trunk in which a separate pair of wires existed for each client subscriber. With call forwarding, there is no physical connection to the client's main telephone service, which is merely call-forwarded to the answering service (usually on a direct inward dial number) at the end of the business day.