It seems that if we want to have a success Blog (which have big earn from it), we must optimize email marketing. Email marketing already becomes heart of making money trough blog. There are many making money Bloggers already have big success by optimize email marketing. As far as I know, these successfully Bloggers use email marketing to maintain their readers, and then make selling trough it. It surely needs hard work because the readers only stay subscribe in email marketing if they have benefit from it. So, it needs some skills to make readers stay subscribes in email marketing, and also to increase number of subscriber lists.