Some questions: (a) Is it too simple? (b) Will people want/need to personalised it? (c) How should we get them to personalise it? (Explicitly or is there some better way?)
The link is here: http://bit.ly/Viewsflowdaily
b) I imagine people may want to personalize it, but I don't think that is something you need to worry about just yet. Keep it lean and mean. But that's my personal opinion.
c) Get them to flag individual items in the mail they get (I want more of this, I want less of this)
One thing I missed when going to the site was the ability to see what the last 2-3 days mails looked like. Before I sign up I'd like to see what I'm getting in to. :)
Bear in mind, though, I am the kinda person that likes clean and minimal and don't really like having to manage online profiles on a gazillion sites.
But say, next to the articles you send out, perhaps have a few tags that categorizes the article. For instance, if it's related to Europe, US, Global, automobile, IT, woodcrafting. Make the tags clickable (unique ID per user in the mail) -- a click on it means "yay, gimme more". How to undo a click, well, I dunno... Some down-arrow like at HN?