It's definitely not encouraged on Reddit, one of the old notes of Redditquite is "if more than 10% of what you submit is your personal content, then you're probably a spammer."

Once, someone submitted one of my blog posts about a rather interesting bug in a AAA game to /r/programming. Over 1,000 net score. Out of curiosity, I submitted the same post myself to /r/games. -7 score.

Actually, Reddit's FAQ[1] says:

> If over 10% of your submissions are your own site/content, you're almost certainly a spammer.

[1] http://www.reddit.com/wiki/faq#wiki_what_constitutes_spam.3F

"Feel free to post links to your own content (within reason). But if that's all you ever post, and it always seems to get voted down, take a good hard look in the mirror — you just might be a spammer. A widely used rule of thumb is the 9:1 ratio, i.e. only 1 out of every 10 of your submissions should be your own content."

From reddiquette.

Your own content != be a corporate shill / spammer.