Has this every happened to you? You find a new site that offers you really great information. You end up subscribing to their newsletter only to find that its not what you thought it would be. Or better yet it was what you thought it was but you interests have changed.
So what do you do? Do you track down the site where the newsletter came from and search endlessly for the coveted “unsubscribe to newsletter” form? Or do you give up and mark the message as spam, so you that it is one less message you have to sift through on your daily adventures to your gmail box?
Whatever you do, the guys at gmail realize that this can be a problem for many. So they have added a new unsubscribe feature to gmail to help alleviate some time for you and some wrongful spam claims for legitimate companies.
Using this feature is pretty straight forward. When you are tired of seeing these nuisances just mark the message as spam, like you normally would. A pop-up window will surface in the middle of the browser asking you if you would like to mark the message as spam or unsubscribe. Its pretty seamless at this point.

It is important to note that the unsubscribe feature is not instant and it may take a few days for the Google Gods to process your request. In addition this feature is not available for all companies just yet.
(Source cnet)