Free is Awesome, I think you are confused with the title of the Post, Let me explain, FREE the most Popular word on the web, everyone wants everything for free like Digital Downloads or any other services etc , so you can offer free Stuff on your Blog.
So why Free is Awesome?
If you are offering something for free people will love it, and you will get great attention from others one of the great example is Google, Google is offering everything almost free of cost and still earning money, if they start charging for their search engine and other services like Gmail, Blogspot, then 90% of users will leave google.
Because everyone wants these things for free, and Google know the psychology of the Internet users and most of the revenue comes from advertising which earned by their users, you can see advertisements everywhere in blogs, Gmail and other services.
Another great example is LINUX, Linux is an open source Operating system so people Prefer Linux for their professional work, for hosting websites, using as a central servers everyone wants to use Linux but it doesn’t mean that windows and others OS are not good, the main reason is Linux is free.
The benefits of offering Something for Free on your Blog
When you offer something for free on your blog, it works like a magnet and it attracts lots of visitors, people love the word free and they want everything which is available for free, so if you are offering freebies to your visitors or readers they will come again, And at the same time they will promote you for free, for example : if you are offering a service which is free but others are charging for the same kind of thing then people will promote you for free and you will get great exposure and free advertising.
When your readers or visitors get benefits from your free services, then they will mention you on their social profiles Like Facebook, Google + or Twitter and you will get good response from everywhere.
How you can Apply FREE on your Blog
You can offer Free E-Books
This is the well known old method and still very popular, bloggers offer their E-books for free and in return they get Subscribers which gives them future benefits and a Good reader base.
You can also offer free services like Free WordPress Installation service, some other services like Domain name Suggestion Service, Free Logo Designing, I know if you offer these things you will get lots of spam request but you can add some conditions for free services to get genuine requests for your services.
Many Bloggers are charging for reviews but you can offer for free, I know you can earn money by charging money for reviews and consultancy but you can get lots of affiliate sales by free consultancy service, because when someone came to you for starting a new blog, then they need hosting, premium themes and other premium stuff so you can get paid by affiliate sales.
If you have some other ideas to offer something for free you can apply it and test , if it works for you then you can get huge benefits from FREE Stuff.