There are many options for computer telephony software; predictive dialers, auto dialers, power dialers, and ratio dialers. However, the two most widely used are predictive and power dialers.
How do you choose the one that is right for you? To help you answer that question here is a list of the pros and cons of each.

Predictive Dialer

How it works

The Predictive Dialer works on it’s ability to predict when the next agent will be available.

It tries to match the time that a prospect will answer the phone to when an agent will be available for the call.

The agent logs into the dialer and it starts dialing prospects until one answers the phone.

Using the averages of several key variables: talk time, rings before a customer picks up, and percentage of dialed calls answered, etc. The Dialer makes more phone calls to match the agents with new people to speak with, when they finish their current calls.

Advantages of Predictive Dialers over Power Dialers
Very little down time for agents.
Higher rates of speaking with people

Draw Backs
Often calls are “abandoned”, meaning a prospect will pick up and no agents will be available to speak with them.
Lag time. Prospect says “Hello” multiple times with a delayed response from agent. Because agents are not switch over to a call until the dialer detects a live person.

Power Dialer
How it Works

The Dialer calls you

The Dialer Calls then calls the next phone number in your database

The Dialer bridges the two calls together before the prospect answers so you are ready to talk when they answer, no delays.

So as long as you are connected to the dialer it keeps dialing when you are available keeping you busy and productive.

Advantages of the Power Dialer over Predictive Dialers
Increased productivity make 3 to 4 times as many calls as manual dialing. An average of 300 calls a day.
Increased Messaging leave more unique voice messages for your contacts. Meaning you can leave a voice mail while you have already begun to dial the next contact.
You can make sure you tie up loose ends before moving on to the next call such as scheduling callback time, sending emails & faxes, or leaving a voice mail.

Drawbacks
Won't contact as many people as predictive dialer
The Difference
The Predictive Dialer is a quantity approach. The Predictive Dialer allows you to make more calls and speak with more people with the drawback being you are going to miss talking to some of the people you dial because of abandonment.

The Power Dialer won't make quite as many calls. However, the quality of the calls will increase dramatically, due to no abandonment. Agents are also able to tie up loose ends before moving on to the next call. There is also an ability to set up automated processes with the Power Dialer Software allowing you to automate your processes of sending emails, voice mails and much more without actually having to do it live.