RSS, Email and 1-to-1 Marketing
To my way of thinking, RSS is most effective as a broadcast medium while email is most effective as a narrowcast medium. When we're broadcasting, we're trying to generate buzz – an awareness of who we are, what we do, and why we're good people. We're interested in the aggregate effect: how many readers, reader retention, and the like. But when we're narrowcasting, we're trying to elicit a specific reader action. Our focus is on the individual response.
In 1-to-1 Marketing, we want to take members of our broadcast audience and convert them to narrowcast and eventually customer. The evolution from broadcast to narrowcast to customer necessitates a loss of anonymity. We develop more information about individuals so that we can target information and proposals for them.
If RSS is to play a significant role in that evolution, then it needs to distinguish between readers and become part of the process of learning about individual readers. Returning to yesterday's request for a standard block of [anonymous] IDs, many people won't want to be a part of that process. It's best to recognize that and provide a mechanism that works within your overall marketing effort.