It's simply maddening when you just want to leave a voice mail for a friend and you have to listen for up to 15 seconds of instructions from the service provider. It goes something like this; if you would like to leave a voice mail for this person press 1(or 3) to leave a call back number press 5, when you are finished press 1 for more options or hang up.
Of course there is a pause between each instruction. Are they doing that in hopes they will be able to charge me an extra minute? Why can't they offer an option 'to skip this message in the future press 0?. I think the service provider should not charge anyone for the time the customers are forced to listen to the instructions. The whole point of getting to the voicemail is to LEAVE A MESSAGE!
What is the purpose of a call back number anyway? Who really uses this feature? If you want someone to call you back at a different number simply leave that information in the voicemail message! Otherwise all phones have a caller id feature.
Even if your phone is off and your friend leaves you a message but no number, you are still able to get the calls information (time, date, number) simply by pressing 5 (for Verizon customers) when you are retrieving your messages. For other service providers you are going to have to listen to the menu options when you first access your voicemail before checking the messages in order to discover what number to press to get the information.
In a world where everyone wants things yesterday, I find this to be an unnecessary inconvenience.