Honestly, there are a myriad of opportunities for a blog website owner, to promote their RSS feeds, through a rich collection of RSS Feed Directories on the Net. You could spend a lot of your time simply subscribing to each and every individual directory. It is a gold mine of opportunities to promote RSS feeds to your site. Here is one directory alone, that is worth your visit: http://www.rss-specifications.com/rss-submission.htm
You can also Google the name under “RSS Specifications.” Happy blogging to all, and have a great day!