Hi Tim,
Vumber will allow you to use a different phone number for each marketing
channel you want to track and each phone number can have its own
voicemail message.
HOWEVER..Vumber has significant limitations. My biggest issue is that if you want to forward calls that come in to more than one phone (like you and a partner) it does not sync. So I can't see if my partner took the call and vice-versa. You have to go to your Vumber account online to look it up. My second biggest issue is about texting. If you have your texts going to more than one phone, it randomly picks which phone number the message goes to. So you could be in the middle of a text conversation only to have the reply go to the other person's phone. My third issue is texting does not support pictures and has a character limit.
All that said, if your calls and messages only get forwarded to one phone number and you just want something to track initial calls from your marketing, Vumber could be an option for you.
If you want something more high-end and professional - RingCentral is worth checking out