Good ad copy is the key. FFA Pages - Can increase links popularity with the search engines. This makes automatic posting absolutely essential. These notes naturally include their sales pitches. Spam - Blasting your website url and a thinly disguised invitation to visit your website to millions.
Reputation is key to building a growing business in many online industries.
Posting to a list with over 100,000 members such as Links Exchange Digest WILL generate traffic. It's even worth the effort to research the answer to a difficult question so that you can respond. Only post if it's helpful. Sometimes posting a picture or banner draws more response. This is a Proven, Major source of traffic for many sites.