After reading some of the responses its funny, I hear "seo's inflating their vaule" and "Whats canonical issues" ... 1. Some SEO's do inflate their value, honestly most hackers here don't need one; our best clients (mutually beneficial) are the ones who have a site, but its old, out dated and not producing like it should. A lot of people don't have the time to monitor their back links, check their title and alt tags…
Anecdote: at the last place I worked, we had a guy come in for an interview. Bright guy, and came across as being straightforward, but he was really insistent about having an 'ongoing' type of deal, whereas the boss already had read a lot of what the guy knew, and so decided against it. I think the boss might have sprung for a day or two of consulting, but certainly wasn't going to go for anything more than a one-off.