Your e-mail is important to us

As a refugee from the call centre industry, Chris Brogan’s post arguing that businesses would be better off investigating other channels of customer service than obsessing about call centre performance really hit home with me.
As I say in the comments to Chris’s post, one of the important things for businesses to learn is that customers who contact you via a given channel (e-mail, for example) probably want to keep the conversation going using the same channel. I used to manage an e-mail enquiry service that was a sideline to a larger call centre, and one thing I asked my staff to do was to sign off every e-mail by inviting the customer to e-mail again with any follow-up, rather than just saying “if you have any questions, please call us”. If they wanted to make a phone call, they would have done so already.
This does have some technical and procedural implications–you need to make sure the e-mail address you’re sending from is not one of those “unrepliable” addresses (a huge peeve of mine), and you need to try to route follow-up e-mails to the person who answered the original enquiry wherever possible. But in my experience, if your turnaround time and the quality of your replies are good enough, those weird customers who prefer to communicate in writing really appreciate it.
I’m one of those customers, and by way of contrast, here’s a really bad experience I had earlier this year:

Here are two sentences:
