According to google - Don't feel obligated to purchase a search engine optimization service. Some companies claim to "guarantee" high ranking for your site in Google's search results. While legitimate consulting firms can improve your site's flow and content, others employ deceptive tactics in an attempt to fool search engines. Be careful; if your domain is affiliated with one of these deceptive services, it could be banned from our index. Source
This means don't hire 100$ SEO "experts' or so called SEO's from India And yea NOBODY can ofer 100% ...
hmm, i agree with W3bmaster, just use the high quality one...SEO service are not to fool search engine, but telling them witch one is the best...how people can rank on Google search engine if not use SEO service (and they don't know how to do that also don't have time), the only option is only use Google adword?, look like Google trying to force all people to use their adword hahah...bad one