Publishing both is useless, because it’s likely that services will end up polling both of them, to identify new content. It is very hard for them to be 100% sure that they actually contain (and will always contain) the same information. You know that polling your blog or service is stupid… don’t make twice as stupid.
Yet, if you publish both ATOM and RSS, make our lives easier in two steps :
- Remove the extra
<link href="...">, by keeping just Atom or RSS
- Add a 301 redirection from one to another, so that you’re not messing with your existing pollers (as they should probably follow redirections and be able to parse either format) : with Apache it’s as easy as:
RedirectMatch 301 /statuses/user_timeline/(.*)\.rss http://twitter.com/statuses/user_timeline/$1.atom
No more excuse for not doing it! Please note that I am not discussing whether you should keep ATOM or RSS. I’d go for Atom, but that’s a not the case for everybody.