It's easy to google voice broadcasting and start dealing with the first company you see.  However, this is not shopping for a new lego set for your kids.  This is about your true ROI.

With the wrong company, you have lost your ROI, most likely.  This is an industry where experience is paramount.  Experience is necessary.  Experience is not something to play around with.

Reason 1:  They usually have a very new relationship with their provider.  That means pricing will not be competitive. 

Reason 2:  Their relationship with their provider needs to be proven.  This industry is fickle.  It's easy to lose a contract --- that means you'll lose your voice marketing campaigns.  None of it your fault.

Reason 3:  Customer service is extremely valuable, particularly in this voice broadcasting industry.

Simply find the right company that  has longevity and customer service experience.