What is a useful place in search results? Ideally, you need to be in the top three search results returned. More than 70% of searches are resolved in these three results, while 90% are resolved on the first page of results. So, if you’re not in the top three, you’re going to find you’re missing out on the majority of potential business—and if you’re not on the first page, you’re going to miss out on nearly all potential business.

If you’re using SEM as a strategy, you’ll need to test and evaluate your keywords. A good rule of thumb is that for every 100 clicks you get, you’ll get between 3 and 10 enquiries. So, to conduct an efficient test, you’ll want to test around 1,000 clicks. That means setting your budget for Adwords at 1,000 times the cost of the click. If you find that this is going to cost too much, you’ll need to find other keywords or a different marketing strategy.
Website owners recognized the value of a high ranking and visibility in search engine results,[6] creating an opportunity for both white hat and black hat SEO practitioners. According to industry analyst Danny Sullivan, the phrase "search engine optimization" probably came into use in 1997. Sullivan credits Bruce Clay as one of the first people to popularize the term.[7] On May 2, 2007,[8] Jason Gambert attempted to trademark the term SEO by convincing the Trademark Office in Arizona[9] that SEO is a "process" involving manipulation of keywords and not a "marketing service."

First, it’s important to know that not all backlinks are created equal. Those published on PR0 (“PR” stands for “page rank”—the “0” means the lowest value) sites offer very little weight in search; those published on PR9 (the highest page rank) sites offer very great weight in searches (in fact, a single backlink on a PR9 site might be enough to deliver top-three rankings for a keyphrase in some cases). Examples of high page rank sites include Wikipedia, the BBC, The New York Times, Mashable, etc.
How does it work? In essence, you use Google Adwords (or another search engine’s equivalent – depending on the market you work in; in China, you’d be looking at Baidu, for example) to place bids on keyphrases; you write an advert based on that keyphrase; the search engine places the advert near the top of the search rankings, and you pay the amount of the bid every time someone clicks on your advert.
Getting unique and authoritative links is crucial for higher ranking in the SERPs and improving your SEO. Google's algorithm on evaluation of links evolved in recent years creating a more challenging process now to get high quality backlinks. External links still matter and aren’t obsolete, so start working on strategies to get valuable backlinks to improve your search visibility.

Search Engine Optimization