Starbucks provides a great demonstration of how to communicate significant changes.
The home page was replaced with a letter from Howard Schultz, addressed to all customers.

At the bottom where links to copies of a letter and a voicemail from Howard Schultz to all Starbucks partners (employees), together with a link to a Questions and Answers page [...]

To engage with customers, it is no longer enough to have an email address and customer service number on one’s website. Today, people want to interact with and engage businesses via their chosen means of communication, whether that is Twitter, Facebook, discussion forums, or a feedback site like Get Satisfaction.
Companies like Dell, for example, have [...]

Traditional ad campaigns are still valuable, but small acts can be more valuable because people will inevitably share such experiences through the social web. When every customer experience can be easily and widely broadcast, small issues become super important.
Southwest Airlines are using Twitter to make sure the customers’ concerns are addressed:
Because bad experiences are broadcast [...]