I didn't see this earlier and need to respond:
> you can buy positions on hacker news
That's false, as far as we know, and we've put a lot of work into this. If anyone knows otherwise and cares about HN, please tell us at hn@ycombinator.com so we can counteract it. Anti-abuse measures are our priority.
If you don't have specific evidence, please don't say "its no secret that you can buy positions on HN". People repeating things doesn't make it true. In fact, when it comes to matters like this, people repeating things is mild evidence that it's not true.
> various websites sell upvotes for cheap
What websites exactly? I know of one, and we've been tracking their nefarious deeds and banning their customers for a long time now. Don't confuse buying votes with buying prominence. I can't say for sure it's not happening (that would be a Rumsfeldian known unknown), but can tell you for sure that what many accounts are actually getting in exchange for paying these spammers is an instant ban for themselves and their sites.