What are benefits of buying a domain ?

Buying a domain which relates directly to the subject of your blog and is based on significant and well searched for keywords can certainly help traffic to your site. However, there is no advantage whatever in just owning a domain name for the sake of it. You may have a domain name which describes the content of your site well and is likely to come up high in search results but, unless the content of your site is good enough to attract people, give them the information that they want and that they can't easily find elsewhere and is, at the same time, well written enough that people actually want to stay and come back again and again, you have NO chance. First, look at your content. THEN consider buying a domain name ... and also consider paying for hosting. If you use free hosting or a free blog host, you are always at the mercy of the people hosting your page. When you pay for hosting, your site is your own.

Yes, a domain is absolutely the best way to gain more traffic to your site or blog. It is also a great way to gain new readership, create new friends, create new contacts, and many other things that will contribute to your success. I find Wordpress is the best place to have a domain blog. Warning, before you create your Wordpress blog, you must create the blog name first, otherwise your domain name will not be registered with Wordpress. If that does happen - you can easily buy a domain name from GoDaddy, or some other site.