Darren has a good post on blogging partnerships.

Sometimes I receive emails on people seeking a partnership. I am open all ears to new ideas, but there needs to be something beneficial for both parties to start something. Especially if you have never met the person and live on opposite ends of the earth.

My own advice is, if you are seeking a partnership with some try to get to know them first either by emailing them or leaving comments on their blog.

For many bloggers, the number of people who leave comments is sometimes how they determine the success of the post. Definitely, when I post how much I have made from Adsense for a given month draws the highest number of comments.