Preview Dialing can be helpful in calling contacts with a good deal of information in them.  This allows you to review all information on the contact without being rushed into a dialing tone.  

Preview Dialing will put you into the dialing screen shown below, allowing you to view all notes, custom fields, and contact information for a given contact BEFORE calling.  When you are ready to call that contact, click on the green phone number, and your Sales Sling phone will start dialing.  When you have completed a call; disposition appropriately and the next contact from the campaign will automatically be pulled up.

NOTE: When preview dialing, the next contact will NOT automatically start dialing.  It WILL automatically move to the next contact after you disposition the previous one.  

Start Preview Dialing:

To start preview dialing, select the green preview dial button next to the campaign you wish to call.