Why is visual voicemail free for iPhone but not for other phones?

[karcirate]

I recently activated an iPhone on my line -- temporarily -- and found that visual voicemail was included and didn't cost a dime. Can anyone explain why visual voicemail is free for iPhones but if you want it for any other phone it bears a monthly charge?

[Tidbits · Accepted solution]

Apple uses their own servers and not the carrier servers.

[Tidbits]

Also VVM is also free for everyone. The $2.99 is for the premium version. You can search the FAQ and there's a pricing list and shows what you get.

[sprmankalel]

On Android devices with Kit Kat basic VVM is free. The $2.99 monthly VVM provides a text transcript of your voicemails.