Google is a major generator of organic traffic. Most of the webmasters use it for marketing purposes...
I use Google adwords. The results vary. It is difficult when you don't have a huge budget to compete.
Google is the biggest source of organic traffic. Everyone try to improve their google search results ranking in order to get lot of traffic.
Well, considering Google is the largest search engine on the internet with over 60% market share it's very politically correct to say they are the best source of organic traffic. Considering if done properly and the fact it costs nothing (unless you use an SEO consultant) it's the best source of traffic you can use.
I think everyone who is trying to sell a product or service will rely on google, it will be difficult for any online business to succeed without google.