One of the things I have been reviewing is pay for e-mail management and marketing tools. I have yet to decide if I want to go forth into this realm because of a few ethical issues I have. Mainly, the freeness of Google.
I can teach people to use Google to manage their entire lives. I manage my entire life with Google. From Android to Google Docs, everything runs through my Google Account. Why? Because:
Storage Upgrades are Cheap!
Reliable, large company, not going anywhere