I recently changed my blog's name from thecommunications.wordpress.com to 1digitalfingerprint.wordpress.com however my traffic has plummeted, I think I have lost my old followers.
7. The final option presented on this screen allows you to discard your current address. This option will permanently disable the address and you will not be able to reuse it. Only select this option if you are sure you will not use the address again. If you want to redirect traffic to the new blog, you can keep the address and purchase the Site Redirect upgrade.
When one chnages's a blog URL (address) without purchasing the site redirect upgrade, and the content in that blog has been indexed by search engines what they have done is broken every URL in the blog. That means when the old links are clicked they all produced 404 (page fnot found) errors. If one purchases a site redirect upgrade then when the links are clicked to the content under the old URLs they are seamlessly redirected to the same content under the new URLs, and they do no lose traffic.
It will take Google and the other search engines about 4 months time until your content is re-indexed under the new URLs.
You will now have to set up a new follow blog widget as the blog has a new URL.