[brunorsini]

I would frame this slightly differently: "How can I make these emails absolutely delightful to users?" Once you nail this you should make it dead simple for happy users to recommend the service to their friends.

As for monetizing the happy and (hopefully) growing base... It won't be easy but I would focus on your main strength: unlike most advertisement inventory you have people's email addresses, which could give you a good head start on the "who" question. Maybe you could even ask an optional question or two as part of your sign up process to give you more data on your users, and based on the combined info you get you could write simple scripts to try and extract the most out of each one.

For instance: if the user is in a country served by Amazon, suggest a different product you actually really like on each email you send out (shouldn't be that much work to curate a basic list of things that caught your fancy). Personally I would make it very explicit that you're:

- adding an affiliate link to the product, which helps pay for the service in question

- you actually do use and like the product (for reasons x, y or z)

I would also make it incredibly simple for users to put money in your hat if they choose to. Paypal recurring payments could be an option here - https://www.paypal.com/pdn-recurring.

[bosslee]

hey :D amazon affiliate link is a great idea too, and you are right that I would need to make it transparent for the users. Maybe I could also test on the following hypothesis that "people who loves using-smart phone for photos, might be interested in camera pdts as well" - I could be sharing some of the camera items I brought off amazon.

And I really like the way you rephase my question."How can I make these emails absolutely delightful to users?"

Thanks