Using affiliate links on social networks and especially twitter seems to a somewhat untouched subject. However, applying a good strategy and a transparent model I’m convinced that there’s room for affiliation on twitter without being seen as a spammer. By the end of the day, people who don’t like what you tweet will unfollow you.
I quote Jeremiah Owyang’s opinions on the matter :
1. Make sure it lines up editorially with your personal brand, promoting a product that people don’t associate you with will raise eyebrows.
2. Disclose it’s an affiliate link, perhaps with a hashtag #affilliatelink.
3. Be sincere about your recommendation. If you truly love that product you’re promoting, perhaps write a review on a blog first, explaining why.
4. Be fully transparent before people follow you: Create a link from your Twitter profile page that is up front about how you use Twitter, and explain your intentions when it comes to product recommendations and affiliate links.