The initial work in SEO is very tedious and time consuming, but once you start seeing the results, anywhere from 2 weeks to 3 months later, it MUST be maintained, otherwise all the original hard work is for nothing.
Most companies think "oh, I'll cut that expense and save a few bucks" but the truth of the matter is, they wind up loosing alot more than "a few bucks" when their rankings fall, and then they are playing catch up trying to get back to where they once were...
Anyway, while SEO is one part of a successful marketing plan, one must also consider complimenting it with such things as an affiliate program, as well as an aggressive Sponsored Search Marketing campaign.
Stop by and get some info, even hit us up
http://www.revenuebox.com