what about negative term seo for your competitors? porn links don't work, people have tried, spamming shit spam links doesn't work, people have tried, if you cant positively promote a site with them, why would it work negatively?
how about "company name review" and boost up a bad review, try to get that bad review to rank when you search "company name", try hard enough and when you google "company name" it will be:
Spot 1:
Title: Company Name Corporate Website
Desc: Blahbla crap we are the best and everyone else sucks buy from us because we are awesome! and our products are made in the USA"
Spot 2:
Title: Company Name HORRIBLE - Don't waste your money!
Desc: This is a personal experience with Company Name and their awful services, slow shipping time, and general disregard for my order and money"
just some food for thought
edit: and ice it with your company ranking third, optimize sporatically (dont over do it) for their main product name or company name, even w2.0 pages linking their type of products that you offer and boost up so when they search "company name" you show up second, "company name review" and your 2.0 or landing page shows second, third, or as one of the main images in the results ???? profit