If a SEO firm promises to put your site high on the SERPs within a period of 90 days (or any other period of time), then that's a red flag. A company is not reliable in such case. No company or search engine optimization expert can guarantee the period of time. No one knows how much time it will take to put your site to top of search engines. SEO is unpredictable. It might take 3 months for small niche websites, or it might take 2 or more years for very competitive site to rank high. So whenever someone is telling you to put you on the top of SERPs, don't fall for that. You should discuss how much time it will take approximately for a SEO firm to do the job, but be patient. SEO is a long and ongoing process.

Link building, keyword rich and original content and article marketing are some of the proven SEO techniques that webmasters utilize to gain the position in the coveted Google rankings. Usually, webmasters hire professional SEO companies for this purpose that keeps a vigilant eye on the ever changing Google algorithms and accordingly makes the required changes in your website so as to attract the web crawlers and help you raise high in the SERPs (Search Engine Result Pages) of Google.

Within this ethical framework, search engines are allowed to improve their search results or die, to be replaced by better search engines; the quality of Web sites in the search results improves, benefiting the owners of those Web sites to the detriment of lower quality Web sites; searchers obtain better results from search engines and are not deceived by advertisements masquerading as search results; and the Web as a whole is a better place. That is the outcome of ethical search marketing. When unethical, deceptive practises are deployed the opposite happens. It is partly for this reason that I believe the SEO industry is sleepwalking towards disaster. Any industry that condones actions that make the Web a worse place cannot rely upon the long term support of the Web's users.

Nonetheless, it is imperative to note that Google doesn't appreciate unethical optimization techniques such as link farms and others. So, websites that are found to gain high rankings by such unethical methods are immediately penalized and at times are even banned from the search engines.