I've done alot of research into reddit. The key is to make everything look natural. Study the front page.
You need to market INDIRECTLY. If you are promoting a product or startup maybe make an indirect image featuring the product and THEN do some direct marketing through the comments. Multiple aged accounts, proxies the whole shebang. Reddit looks like an easy community to fool but they aren't. My favorite tactic is to talk about some other product and then post a blog post about it. In the blog post you predominantly mention your product instead. Also create fake blog comments. Lots of users will upvote/downvote purely based on the title and bypass the article entirely and go straight to comments. You can also do marketing in the comments using your fake accounts.
You have to get elaborate about it. The reddit users do have their vulnerabilities. For example, most of them are very liberal, politically. So if you want easy upvotes just bash republicans and promote liberal ideas. People will upvoate purely based on that, even if you are spamming (your blog/product) lol.
Also if you are planning on making money through advertising, don't even bother. 90% of reddit uses adblock so you make zero money. The only real benefit is that reddit users are very likely to share content on the site but they won't share it if its a spam blog.