New York: WordPress.com provides free Web hosting and a built-in social network of WordPress blogs on its servers. However, there are many benefits to having a self-hosted WordPress blog on another Web host, including greater customization options and more flexibility with monetizing your site. Bluehost is one of the WordPress Web hosts most suggested by WordPress.org, and it gives a complete self-hosted WordPress solution with a one-click installation method. If you're switching your WordPress blog from WordPress.com to Bluehost, you can keep all of the comments on your posts by exporting your content from your old blog and importing it to your new blog on Bluehost.
Export WordPress.com Comments
Log in to your WordPress.com account, and click the "My Blog" tab in the main menu.
Click the "Blog Admin" link under the blog whose comments you want to export.
Hover your cursor over the “Tools” tab in the left column, and then select “Export” from the sub-menu.
Click the "Export" link in the next page.
Select the radio button next to "All Content." Click the "Download Export File" button to download the XML file containing all of your blog's pages, posts, comments and menus. This file usually downloads to your default download folder. For most Windows users, the folder is called "Downloads" on your hard drive.
Importing to Hosted WordPress
Log in to the admin dashboard of the WordPress site into which you want to import your comments. Bluehost's one-click installation automatically generates a WordPress admin username and password for you, which you can locate in the automated system email you received when you installed the software on your server.
Hover your cursor over the "Tools" tab in your WordPress dashboard. Select "Import" in the sub-menu.
Click the "WordPress" link from the list of available blog platforms from which you can import. A pop-up dialog box launches automatically, prompting you to install the WordPress Importer plug-in, if you don't already have it installed. Click "Activate the Plugin & Run the Importer" to finish activating the plug-in.
Click the "Choose File" button and browse your hard drive for the XML you downloaded from your WordPress.com blog. Double-click the file to select it.
Click the "Upload File and Import" button to begin importing your content.
Assign an author to your imported posts. You can either create a new user, for which WordPress will generate a random password that you can change later, or you can assign the content to an existing user on your site.
Click the "Submit" button to complete the process.
Importing your content via XML brings in all the posts and pages that correspond to your comments as well as the comments themselves. However, your media library won't import. You'll have to re-upload your media manually to your new site. Information in this article relate to sites running WordPress 3.5.1. It may differ a little or considerably with other versions or products.
Read more: WordPress CMS Development