Since social media marketing first came to be, strategists and markets have been getting smarter and more careful with the way they go about collecting information and distributing advertisements. With the presence of data collecting companies, there is no longer a need to target specific audiences. This can be seen as a large ethical gray area. For many users, this is a breach of privacy, but there are no laws that prevent these companies from using the information provided on their websites. Companies like Equifax, Inc., TransUnion Corp, and LexisNexis Group thrive on collecting and sharing personal information of social media users.[107] In 2012, Facebook purchased information from 70 million households from a third party company called Datalogix. Facebook later revealed that they purchased the information in order to create a more efficient advertising service.[108]

Companies that employ overly aggressive techniques can get their client websites banned from the search results. In 2005, the Wall Street Journal reported on a company, Traffic Power, which allegedly used high-risk techniques and failed to disclose those risks to its clients.[15] Wired magazine reported that the same company sued blogger and SEO Aaron Wall for writing about the ban.[16] Google's Matt Cutts later confirmed that Google did in fact ban Traffic Power and some of its clients.[17]

You can confer some of your site's reputation to another site when your site links to it. Sometimes users can take advantage of this by adding links to their own site in your comment sections or message boards. Or sometimes you might mention a site in a negative way and don't want to confer any of your reputation upon it. For example, imagine that you're writing a blog post on the topic of comment spamming and you want to call out a site that recently comment spammed your blog. You want to warn others of the site, so you include the link to it in your content; however, you certainly don't want to give the site some of your reputation from your link. This would be a good time to use nofollow.
AdWords is recognized as a web-based advertising utensil since it adopts keywords which can deliver adverts explicitly to web users looking for information in respect to a certain product or service. It is flexible and provides customizable options like Ad Extensions, access to non-search sites, leveraging the display network to help increase brand awareness. The project hinges on cost per click (CPC) pricing where the maximum cost per day for the campaign can be chosen, thus the payment of the service only applies if the advert has been clicked. SEM companies have embarked on AdWords projects as a way to publicize their SEM and SEO services. One of the most successful approaches to the strategy of this project was to focus on making sure that PPC advertising funds were prudently invested. Moreover, SEM companies have described AdWords as a practical tool for increasing a consumer’s investment earnings on Internet advertising. The use of conversion tracking and Google Analytics tools was deemed to be practical for presenting to clients the performance of their canvas from click to conversion. AdWords project has enabled SEM companies to train their clients on the utensil and delivers better performance to the canvass. The assistance of AdWord canvass could contribute to the growth of web traffic for a number of its consumer’s websites, by as much as 250% in only nine months.[30]
As the number of sites on the Web increased in the mid-to-late 1990s, search engines started appearing to help people find information quickly. Search engines developed business models to finance their services, such as pay per click programs offered by Open Text[7] in 1996 and then[8] in 1998. later changed its name[9] to Overture in 2001, was purchased by Yahoo! in 2003, and now offers paid search opportunities for advertisers through Yahoo! Search Marketing. Google also began to offer advertisements on search results pages in 2000 through the Google AdWords program. By 2007, pay-per-click programs proved to be primary moneymakers[10] for search engines. In a market dominated by Google, in 2009 Yahoo! and Microsoft announced the intention to forge an alliance. The Yahoo! & Microsoft Search Alliance eventually received approval from regulators in the US and Europe in February 2010.[11]
Optimizing a website may involve editing its content, adding content, modifying HTML, and associated coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines.[citation needed] Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic. By May 2015, mobile search had surpassed desktop search.[3]