One of my clients has invited all of their clients to follow them on twitter and about 45% of their clients do. They then sent out an extensive customer survey that 90% of their clients filled out and sent back. My client then sent out a thank you tweet for all who participated. When a couple of clients mentioned that they did not receive a thank you for participating in the survey the management said that they sent out the thank you tweet. Managements response was if you wanted the thank you then you should have been following them on twitter. Needless to say, customer service received a few phone calls indicating that these loyal clients were not going to be so loyal in the future because of the way they were treated.
Moral of the story, it is good to use technology but you also need to use some less technological ways to make sure all bases are covered.