Contact list of all blogs using RSS feed Aggregators

RSS feed aggregators. They make it possible to import into your blog, the RSS feed posts from another blog, pretty much verbatum. Simple concept. I am going to be marketing a product to this niche market, and need someone to research blogs out there that utilizing RSS feed aggregators, or duplicating content in general, and get me their email address information either through the internic whois domain name listing information, or via the website itself. The product is not spam, it is something that is going to help these people grow their google rankings. I just dont have the time to compile the list of emails. You'd need to understand how many RSS feed aggregators there are out there (like feedgator for joomla [login to view URL]) and be able to find websites utilizing that functionality I dont just want an email list of everyone on earth that has a blog. That's not my customer target. My target is only blogs that utilize feed aggregators.