The ability for me personally with my business clients was that I could have an office phone number which they were able t o call at any time without worrying about being charged extra fees or waiting around while trying multiple numbers until one worked! There are so many things you can do wrong when using Voicemail services like this - but we never had issues because our account rep always got back right away if there's ever something going amiss (we've been very happy). We used them primarily just from home/office phones since most people use their cellphones these days anyway; however now i'm working remotely sometimes too where VOIP would be perfect instead :) Our main issue has actually nothing directly related to voicemails though- rather how easy accessability via mobile apps etc makes us feel less important than others who don't care nearly enough ;) They're great overall tho!!