One more thing... You could also use FeedBurner (email notifications) to communicate with your subscribers. However, (as the name implies) it uses your RSS feed, and sends out the latest additions when it's updated (daily or as it happens).

Sledger, wouldn't you manually have to managee opt-ins and opt-outs when using POP? It could be a lot of work with 1000s of subscribers.

Risto