That's a lot of cottages. To my knowledge, Website Results is the first major SEO firm ever to be acquired. It certainly is the first to receive such a high valuation. Any other SEO firm that I can think of remains privately held, so values are hard to come by. Website Results is almost certainly what I would describe as a doorway page firm.
Companies turn to doorway page firms seeking traffic from search engines.
To generate this traffic, doorway page firms create pages they hope will rank well for particular terms, on particular crawler-based search engines. Cloaking allows doorway page firms to bill clients only for traffic they actually receive, plus it protects the coding of successful pages from competitors. Their solution is focused not only on getting additional referrals, but also on making certain that the referrals are highly-qualified, so that there is also the best conversion rate. Their proprietary systems provide a means to measure the incremental traffic, which provides accurate billing. Let me do some translating.