Device Type: desktop
Skip to Main Content Skip to Main Content

What Is the Difference Between Preview, Progressive and Predictive Dialers?

This article was published on August 12, 2021

At Vonage 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 CRM instance and this often raises questions about terminology for outbound dialing platforms.

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

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 Dialer

With a preview dialer 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 Dialer

A progressive dialer 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.

VCC and Salesforce integrated dialing video thumbnail

Watch a dialer demonstration with Vonage and Salesforce

Predictive Dialer

The most intensive solution is the predictive dialer. With the progressive dialer 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 dialer 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 dialers are typically used in very high volume low margin outbound contact centers 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 dialers can overcompensate and end up with more live callers than advisors. This leaves bewildered customers or prospects hanging on a deadline. 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 dialing versus the negative risks on your brand and your team.


We hope this has been a useful introduction to dialers. For more information on our outbound contact center solutions visit our Vonage Contact Center Sales Dialer page.

Informe global de interacción del cliente con los Contact Center
¿Está tu Contact Center preparado para ganarse a los clientes en 2021?
Pedimos a 5000 consumidores de todo el mundo que nos contaran sus mayores frustraciones en materia de comunicación (dos veces en 2020). Descubrimos que sus preferencias y expectativas evolucionaban rápidamente. Este informe arroja luz sobre cómo mejorar la satisfacción del cliente, la puntuación en Net Promoter Score y mucho más.
Tim Kimber
Tim Kimber

Director of Product Marketing at Vonage