If they won't explain it better, why consider them!!

Anyhow, keeping connections with clients is a two way effort. Not only do you keep your client contact database but they do same. This dual effort means that it's hard to lose complete contact. Besides we have email contact as well.

-> Something's scary about your post. Most companies keep a land line number. Are you trying to go completely cellular or internet? It may be too early to do that.