In 2007, U.S. advertisers spent US $24.6 billion on search engine marketing.[3] In Q2 2015, Google (73.7%) and the Yahoo/Bing (26.3%) partnership accounted for almost 100% of U.S. search engine spend.[4] As of 2006, SEM was growing much faster than traditional advertising and even other channels of online marketing.[5] Managing search campaigns is either done directly with the SEM vendor or through an SEM tool provider. It may also be self-serve or through an advertising agency. As of October 2016, Google leads the global search engine market with a market share of 89.3%. Bing comes second with a market share of 4.36%, Yahoo comes third with a market share of 3.3%, and Chinese search engine Baidu is fourth globally with a share of about 0.68%.[6]
How do you figure out what keywords your competitors are ranking for, you ask? Aside from manually searching for keywords in an incognito browser and seeing what positions your competitors are in, SEMrush allows you to run a number of free reports that show you the top keywords for the domain you enter. This is a quick way to get a sense of the types of terms your competitors are ranking for.
Did you know that nearly 60% of the sites that have a top ten Google search ranking are three years old or more? Data from an Ahrefs study of two million pages suggests that very few sites less than a year old achieve that ranking. So if you’ve had your site for a while, and have optimized it using the tips in this article, that’s already an advantage.

So if you think about it, SEO is really just a process of proving to search engines that you are the best site, the most authoritative, the most trusted, the most unique and interesting site that they can offer to their customer - the searcher. Get people to talk about you, produce good quality content, get people to link to you, and Google will be more confident that you are the best result that they can offer to their searchers, and that’s when you will start ranking on the first page of Google.
Paid inclusion is a search engine marketing method in itself, but also a tool of search engine optimization, since experts and firms can test out different approaches to improving ranking and see the results often within a couple of days, instead of waiting weeks or months. Knowledge gained this way can be used to optimize other web pages, without paying the search engine company.
In March 2006, KinderStart filed a lawsuit against Google over search engine rankings. KinderStart's website was removed from Google's index prior to the lawsuit, and the amount of traffic to the site dropped by 70%. On March 16, 2007, the United States District Court for the Northern District of California (San Jose Division) dismissed KinderStart's complaint without leave to amend, and partially granted Google's motion for Rule 11 sanctions against KinderStart's attorney, requiring him to pay part of Google's legal expenses.[70][71]

Thanks for the helpful information discussing the differences and similarities between SEO and SEM. The information was enlightening because a search engine optimization company like the one that I own is relatively new at starting. We believe everyone should always check out their sources because every different perspective is very different so all approaches can be understood differently.