I actually did a semi-controlled experiment a while back and submitted a series of blog posts I was writing, all on the same topic. There were seven of them all together. On four of them, I asked a small number (a single digit) of people to upvote the story. For the other three, I didn't. All four of the gamed stories ended up near the top of the home page. The other three didn't get a single upvote. If you do the math you will find that this is a statistically significant result. (And I have since submitted many other stories. Not a single one has gotten more than one upvote.)
The trick is to get enough upvotes early enough to get onto the home page. It doesn't take much, it just has to be fast. Once you're on the home page, people actually pay attention and you get a lot of organic traffic. But your odds of getting off the new page at all unless you game the system are extremely small.
Some changes that would help the situation:
1. Provide some incentive for people to read the new page. I'm not sure what this incentive would be, but the fact that very few people read the new page is the nub of the problem.
2. Incorporate the submitter's karma into the ranking of the new page to allow stories submitted by high-karma users to stay there longer. Depending on the time of day, a story typically has between 30 minutes and an hour before it drops off the new page, after which it will surely never be noticed.
3. Don't start the timer on a story when it is submitted. Instead, start it only after some time has elapsed (at least a few hours) or it gets its first upvote.
4. Make it cost something (like a karma point) to submit a story. Throttle the cost so that submitting a large number of stories in a short period of time costs more.
Quite probably. If you know a good way to distinguish between such a circumstance and a deliberate voting ring then let the site designers know!
I'd just avoid voting on your collegues/friends' stuff. HN is so highly trafficed that if it was going to get near the front page it would anyway without those few extra votes and if it wasn't it wouldn't anyway even with those few extra votes.
EDIT: Actually, cancel that last bit. I see some of the items on the front page currently don't seem to have many points so a few friends voting could make a difference. Though I'd still refrain as most major sites that include user voting will have this sort of voting ring detection so you will get nobbled at some point.
http://paulgraham.com/better.html
Spammers aggressively try to game email. Likewise, promoters aggressively try to game HN.
How do promoters try to game HN?
Voting Rings
If you're not familiar with that term, a voting ring is basically a group of people (or robot accounts) that collude to upvote certain stories.
It shouldn't be surprising that Paul Graham would take a similar approach to Voting Rings as he did to Spam.
In one of your comments, you said: "I know it doesnt work because I click upvote and it doesnt assign any points while a friend sitting right next to me could do the same thing and assign points."
If you and another account always seem to upvote the same stories, yet no one else seems to upvote them at the same rate, then it starts to look like a voting ring.
Just like with spam, there will be false positives. I've heard of this happening to folks who have an audience that are also largely HN users. When they send out a new post, then many of that audience upvotes the post, but since it's often the same people, the voting-ring protections get triggered and the post will quickly drop off the front-page.
There are probably many signals that pg uses to detect voting rings. I'm sure they're not perfect, but I'm glad they're there. Otherwise HN would be overrun by aggressive promoters and HN would quickly lose its usefulness.
Advice to promoters: 1) create valuable content that helps users be awesome (no one cares how awesome your brand is), 2) submit it to HN, and 3) don't ask your audience to upvote it
Many promoters just can't help themselves and will do #3 anyways. Just be forewarned that you will likely trigger the voting-ring protections and will be shooting yourself in the foot.
For help with #1, see http://shelby.tv/video/vimeo/54469442/kathy-sierra-building-...