Just like attempting to formalize it may be a mistake, thinking HN might be too big is an equally limiting mistake. Ideally the pay-it-forward concept would encompass every individual globally and as such it has no upper limit.
When in doubt, just concentrate on what you can do :)
> jacquesm posts 'I'll promote one startup on launch day that helps another HNer in a meaningful way.'
I've already been doing that for a while, I was just wondering if it might be useful to give that some bigger shoes.
I'm sure that any of the sites here that are large enough to be selling ads would have some unsold inventory or inventory that they could miss without any pain whatsoever.
If you have to set that up on a per-instance basis it is a lot of work (it is for me) so that might take the sting out of it and make it more practical.
bloggergirl offer help accepted by kabuks resulting in this post.
I wonder if HN isn't a little big for this though.