"Search advertisers are offered two basic marketing models, paid-ads and free organic ads."
They call it
free organic ads, but how free is it if you consider the amount of time used to get into the top ten position?
The paid may even be much cheaper.
How many found gold in the Klondike Gold Rush?
http://www.nps.gov/klgo/
The internet medium (industry) is young. But less then 10 % of the sites on the internet make money, money to pay their employers or feed their owner. As it matures, it will in my view (but I may be wrong), be more and more difficult for a new startup company to succeed. And advertising may be more expensive. Tv Ad is very expensive, and not for small companies in Norway. I do not know how it is in other countries.
Conclusion:
1. To succeed with "free" organic Ad on the internet in the future, you have to invest more and more of your time in learning the different
SEO techniques.
2. More and more of Ad words will be bought by companies with a large (huge) Ad budget.
3. As allways, the small fishes will feed the big sharks.