If you are planning to start a blog on WordPress.com, you should know a few things. First, if you are creating a site that you will want to make money for you, or for your resume, you need to upgrade a buy your own domain name. A subdomain of WordPress looks unprofessional, however, you can use your own domain name with the lowest priced plan. When you upgrade, there are three paid plans available, with the highest priced plan being the only one where you have access to an unlimited number of themes.
Allowing WordPress.com to host your blog relieves you of having to worry about updates and making backup of your blog. WordPress' hosting will affect your SEO; if it is fast, it will help your SEO, but if sites load slowly, it will affect your SEO negatively.
It is so easy to buy both your own domain and your own hosting, and then you can install WordPress from WordPress.org with one click. You can use any templates and plugins you like, and you will have more control over customizing your website. There are major corporations that use WordPress; they use self-hosting and they hire web develops to make their sites truly unique.
WordPress is good for SEO, but when you allow WordPress.com to host your blog, you are dependent on them to have good hosting so your site will load quickly. If you buy your hosting and your site starts loading slowly, you can always download your blog and change hosts.
Before you blame the host, make sure you have not overloaded your blog with too many plugins or you have a theme that loads slowly. With approximately one-third of all sites on the Internet powered by WordPress, it is obvious that many people and organizations are finding ways to make WordPress an SEO powerhouse.