How to do marketing research for blog printing service?

I am working on the service which allows blog owners to distribute their content in a printer form by regular mail. Every blog reader will be able to subscribe to his favorite blogs and receive it as a newspaper.
1) How can I do a marketing research to see how many people are ready to use it and how much they are ready to pay?
2) How can I evaluate the market size for this service?

Thank you

I would ask blog owners to run a poll on their website. Exchange free advertising in your newspaper for them running the poll for a week and sending you the results.

You can also create a website for your idea, and run a poll/survey on it.

Here is what I could think of while approaching this :-

1. Lets start with the total number of blogs out there.
2. Reduce this # to the blogs which are active & popular. Indicators can be services like technorati & tweetmeme, top 100 in each category, pagerank, etc...
3. See how many of these popular blog writers have published books.
4. Find a rough indicator of copies sold (published data, reviews, position in book category, reprints etc.)

That will give you a good idea of how many people buy books based on content which primarily originated from blog posts.

Hope this helps...