WordPress.com is a blog web hosting service provider owned by Automattic, and powered by the open source WordPress software. It provides free blog hosting for registered users and is financially supported via paid upgrades, "VIP" services and advertising.
Ranked in these QuestionsQuestion Ranking
Pro Huge collection of free and paid themes out of the box
Pro Pretty easy to create and maintain a blog
Pro Import from other blogging platforms
Such as blogger.
Pro Bulk media options
Pro Widget management
Pro Support sort post by name
Pro Powerful analytics out of the box
Pro Plugins for every occassion
There are a wealth of plugins that can cater for just about every requirement you may have, and many of these plugins are free.
Con Post must has category else it will be labeled as uncategorized
Plugin cannot be used, custom html/css, Date Permalink cannot changed on free wordpress
Con Slow Speed
Navigating between action took around 3-5 seconds and longer for bulk action.