I'm working on this product by which I hope to convert the visitors who are not willing to commit their email to your service just yet. Our service collects their emails on your behalf to send them updates (which you will send) about their interest/product.<p>For example, let us say you run a phone blog and you have a lot of visitors and very few give out their email addresses. This way you cannot reach the visitors again for a followup update about the things they were interested in. Our service collects the emails of the visitors for sending updates about the particular phone they were interested in. You can then send updates to that list about that particular phone and turn them into returning visitors and maybe make them purchase that phone through a referral link after it is launched.<p>Do you find value in a service like this, that helps you send super relevant updates to your visitors who aren't yet committed enough to give you their email address? Would you pay for such a service?