I've been slowly optimizing a site for my employer, but I don't think the effort to promote his ideas should stop with tuning his web site. What are the first things to think about to spread an idea and increase traffic once you're satisfied with Google's attentions?
Depends on what the website's function is.
Keep getting links from relevent website. Add more content. Post in relevent and popular forums.
I was originally going to post in a lot of forums, but I think this is such a common strategy at this point that anyone who just pops up to post a link looks like they're only their to pimp. :-/
Yeah, it's also called "Spam". The only effective way to promote your site through forums is to become a valued community member, which takes time, and effort.
It also helps when posting in forums, to reply to other people's queries. Don't just put a massage in check out my new site; find someone who can benefit from your site and promote it in their discussion by suggesting it.
The problem with gradually building forum relationships is that your employer always wants to know why he isn't getting better traffic yet! :--/