While I believe that you can do this, most people wouldn't have the slightest clue how. Also, my understanding is that it's highly unlikely someone new to Digg or Reddit will get a submission promoted far. Is that not true?

You'll definitely have to work on it to make it happen - i.e. become active on those sites. However, I only have 288 karma points on reddit and I can get a reasonable success rate when I submit stuff there. The longer your account has existed and the more active it is, though, the better, of course.

Digg is a pain in the ass in that respect. The volumes of "diggs" required to even make a blip are so huge that you'll only make it there if either you've totally gamed it (like that guy who posted that article about it recently), or if you've made it through somewhere else and you're dugg as a side effect. I stopped bothering with it because I kept hearing that the quality of the traffic is also very low anyway (very high bounce rates).

Reddit and HN, however, are relatively easy to promote to, and if you get really picked up very well on reddit (which should happen with 1 article every few months if you're good and write reasonably often), it'll spread to other places too. Articles that succeed only on HN don't seem to spread around too much, however.

The best place so far, though, was Slashdot. Get yourself slashdotted (on their main page), and you can expect 100k+ hits from it, and many links from blogs, and probably you'll get reddited, delicious'ed, dugg, etc, soon after. Be sure that your server is ready to handle it... It's a complete lottery - an actual editor has to decide whether to push your article - but if you win it, it's worth it - so submit there when you have good slashdot content, it's free and might bring you untold amounts of geeky traffic!

Bear in mind also that none of these methods guarantee anything - not even traffic, and definitely no guarantee that people will stick around. But they're not overly hard to achieve if you're a decent writer and have something reasonably interesting to say (those are the hard bits, really).

I didn't realize Slashdot still had that kind of traffic. Good to know. You're right about HN users. They don't tend to Digg or Reddit you much. But they do stick pretty well if your product is in the category, so they're worth quite a bit on their own.

Definitely I would recommend just running a blog on Wordpress.com or TypePad or blogspot. Some service that can withstand the heat of any big press releases. Just in case. You can spend a few bucks to make it look like a subdomain of your main site anyway. Blogging can net you some organic search traffic too.

Last I heard there was a kind of cartel of professionals determining what gets popular and what doesn't. Last I heard was a year ago, though.

That's true on digg, but in my experience, it's not true on:

1) Hacker News

2) Reddit

3) Stumble Upon