That is how long you have to hook a person on a cold voicemail message according to this article on Salesopedia (my bold):

6 Interesting Sales Prospecting Statistics

1.  In a recent survey 95% of salespeople said they can sell - they just need to get in front of more prospects.
2.  Effective prospecting blends both marketing & selling.
3.  Most salespeople HATE to prospect.
4.  The best prospectors often close more business than the best salespeople.
5.  Nearly 60% of high performing prospectors consider the phone ESSENTIAL to their prospecting success.
6.  Decision makers listen to only 9 seconds of a “cold” voicemail before deciding to press delete?

Good points all of them.  If you only have 9 sec., does it make sense to spend it stating your name and contact information?  My thought is that it makes more sense to take an approach that buys you another 9 seconds.  Whatever your approach, know that your window is smaller than you may have expected.

Posted By Derrick Moe | Communication, Sales Techniques | |