What is the Difference Between Preview, Progressive and Predictive Diallers?

Young woman in headphones working on computer while sitting at her workplace

Preview, Progressive and Predictive Diallers

At NewVoiceMedia our core focus is on helping our customers to handle inbound calls with style.  As part of our service customers also get the ability to make outbound calls from their Salesforce instance and this often raises questions about terminology for outbound dialling platforms.

Here is a quick introduction to the options and suggestions as so when each is most appropriate.

Let’s take the example of a telemarketing team who are calling attendees of a recent exhibition.

Preview Dialler

With a preview dialler at the end of a call your advisors are able to see the next call in the list.  It is up to them when to make the call and they may also be able to skip to the next name on the list.  This can be ideal for more complex sales where a bit of research is required between calls to increase the chances of success.

Progressive Dialler

A progressive dialler removes the option of when the next call is made from your advisors.  On completing the previous call (or moving from “Wrap-up” to “Go ready”) the system automatically dials the next number on the list.  This removes the wait time between calls and can improve productivity significantly.

This is ideal where the calls are very similar in nature and advisors benefit from having the system tee up the next call for them.

Watch a Dialler Demonstration

Predictive Dialler

The most intensive solution is the predictive dialler.  With the progressive dialler although calls are made as soon as advisors are available many of those calls incur a long ring time, are engaged or hit an answer-phone – all wasted time with an advisor on the end of the line.

The predictive dialler determines that a percentage of calls will be unsuccessful and therefore over-dials connecting ‘live’ callers to the advisors as soon as they come available.

Predictive diallers are typically used in very high volume low margin outbound contact centres where the efficiency of the advisors and the cost per call are paramount – seconds matter.

The areas to be aware of are two-fold.  As we see in TV programmes, unless managed correctly predictive diallers can over compensate and end up with more live callers than advisors.  This leaves bewildered customers or prospects hanging on a dead line.  To counter this, Ofcom regulations state that no more than 3% of callers can be abandoned in this way.

Secondly, the effect on your advisors should be taken into account.  They are not cogs in a machine.  Having calls delivered to you without respite can reduce their morale and effectiveness with customers.  Time should be taken to weigh up the extra gain from predictive dialling versus the negative risks on your brand and your team.


We hope this has been a useful introduction to diallers. For more information on our outbound contact centre solutions visit our ContactWorld for Sales Dialler page.

Charlie Cowan
Charlie Cowan

Charlie is passionate about cloud computing and how it can help real businesses to run more profitably.

Deskphone with Vonage logo

Talk to an expert.