Lead generation

I came across a new service today which I personally have never seen before and could be a interesting model for future businesses.
There are companies that have generated websites with keywords and traffic-gathering keyword-based advertising programs that provide them with a list of qualified leads for example for life insurance lead or car insurance leads etc...
They are directing visitors to a registration page and then providing the leads to third parties. This means that if you are offering a service in this area, but do not receive a tremendous amount of traffic, you can effectively 'buy' leads from a service specially set up to capture your target audience.
After all, just because you offer a great insurance service, does not mean that you have built the best website or get the most traffic - why not leave that end of things to a service that is designed from the base up to do exactly that?