Of course your content has to be amazing and needs a few backlinks from industry leaders or authority sites. Also the most important part of your blog post is the bottom section where you have your call to action to convert the reader into a subscriber, so don't ever use a generic click here type CTA.
E.g. If your blog post is about 10 ways to lose weight, then add a resource box below which says "It's time to get started, download this FREE time-line pdf I prepared for you which helped me and 1000 members of this website lose over 10 lbs in 22 days" and bam.. there you have a new signup!
P.S. Goes without saying but you must give good advice. You have to win their trust, the article, the pdf must give them what they're searching for (give them 80% and remaining 20% after payment).