What is a multi-line dialer?
A multi-line dialer lets one rep call several phone numbers at once and talk to whichever contact picks up first.
Multi-line dialer vs parallel dialer
The two names usually describe the same thing. Multi-line points to the number of lines dialed per rep; parallel dialer points to those calls happening at the same time. Products differ in how many lines a rep can run at once. More lines mean more attempts per minute, and more chance that two people answer together.
Why it matters for sales teams
On cold lists, many attempts end in no answer or voicemail. Dialing several lines at a time shrinks the waiting between conversations, which is what drives conversations per hour.
When evaluating one, look past the line count. Ask how quickly the rep is connected after the prospect says hello (connection delay), what happens when two people answer at once, and how each attempt is logged to the CRM.
Example
A rep starts a multi-line session on a list of 150 contacts. Three numbers ring. Two go unanswered and one is picked up by the prospect, who is connected to the rep. The unanswered attempts are logged, and once the conversation ends, the next set of numbers starts ringing.