One of my contacts had an email message that needed to go out quick. We set up an email broadcast account for a non-political mailing and started testing within 30 minutes. I imported the email list and was able to deploy the email message within one hour for an important event in the next 48 hours.
Email broadcasting works. If your email list is to contacts who know you and trust you, the open rate and results will be high. If the email list audience is not known to the sender, then it might make sense to throttle the mailing as it is being deployed which will allow it to go through spam, the ISPs who might block the mailing, or any potential complainers.
The bottom line is that when email broadcasting communication works successfully, it makes for a great harmony of product and services.