It's going to get a lot harder to use the old "check's in the mail" excuse. The United States Post Office is launching "Informed Delivery" which provides a scan of the envelopes of all the mail I am receiving later that day. I can go to my USPS account on line and check to see what will be in the box when the carrier arrives.
Do I really need to know this? I assume that the post office is trying to accommodate the mobile lifestyles of people who can't conveniently check their mail or who want to see if it is "worth it" to head to the box. But knowing a letter or bill or check is there does little to facilitate its processing, and heaven knows I don't want anyone opening my mail and scanning that too. All it seems to do for me is remove the element of surprise and delight when a true handwritten letter greets me after I turn the key.
Where is that line between helpful information and overload? Think about what you provide to your customers and watch that you don't cross it like the post office did.