Even though selling your blog or website is something you shouldn't be thinking about at an early stage in your web presence, a lot of people go that way when they need large amounts of money instantly. People have even begun selling Squidoo lenses for a few dollars a piece depending on the ranking at Squidoo.
Financially speaking, the true worth of your blog is dependent on many different factors such as the assets you own, if you're running a dot com company, the kind of revenues you're generating, the kind of revenue growth you're looking at, blah blah blah. But to get a rough estimate fancy algorithms can calculate how much a blog or website is worth depending on the number of backlinks it has. These can be seen as evidence of popularity and are easy to spot.
Here's a great website that allows you to calculate the value of a web address depending on the number of backlinks it has: http://directory.sootle.com/website-worth/. Have fun checking out what all the big-wigs on the internet are worth!
