It doesn't get much more straight-forward than this - you can make money by selling your whole blog. There's a few different ways that you can go about this and you'll get a better price if you have proven revenue coming into the site regularly, not to mention an old domain that gets a lot of organic search engine traffic.

You can go down the route of finding a buyer on your own (maybe you've received a personal offer via email, phone, etc.) or you can go through a third-party auction site like Flippa, SitesIndeed.com or you can advertise your listing within the Digital Point forum.

Advantages: If you're looking for a lump sum and aren't interested in taking the site any further then this could work out to be a very lucrative option. Some blogs can be worth into the $100,000s if they're really old and bring in large quantities of traffic.

Disadvantages: Well, this isn't exactly a sustainable revenue model for your single blog as it's going to be a one-off fee that forfeits your right to make any more revenue from it in the future. On top of this, pricing your blog can be pretty tricky.

My advice here would be to get your blog valued from multiple sources before offering a cost - also, if it's worth a large amount, make sure you put a reserve on the auction!