Twitter allows companies to promote their products in short messages known as tweets limited to 140 characters which appear on followers' Home timelines. Tweets can contain text, Hashtag, photo, video, Animated GIF, Emoji, or links to the product's website and other social media profiles, etc. Twitter is also used by companies to provide customer service. Some companies make support available 24/7 and answer promptly, thus improving brand loyalty and appreciation.
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.
Engagement with the social web means that customers and stakeholders are active participants rather than passive viewers. An example of these are consumer advocacy groups and groups that criticize companies (e.g., lobby groups or advocacy organizations). Social media use in a business or political context allows all consumers/citizens to express and share an opinion about a company's products, services, business practices, or a government's actions. Each participating customer, non-customer, or citizen who is participating online via social media becomes a part of the marketing department (or a challenge to the marketing effort). Whereas as other customers read their positive or negative comments or reviews. Getting consumers, potential consumers or citizens to be engaged online is fundamental to successful social media marketing. With the advent of social media marketing, it has become increasingly important to gain customer interest in products and services. This can eventually be translated into buying behavior, or voting and donating behavior in a political context. New online marketing concepts of engagement and loyalty have emerged which aim to build customer participation and brand reputation.
Gaining Google's trust doesn't happen overnight. It takes time. Think about building up your relationship with anyone. The longer you know that person, the more likely that trust will solidify. So, the reasoning is, that if Google just met you, it's going to have a hard time trusting you. If you want Google to trust you, you have to get other people that Google already trusts, to vouch for you. This is also known as link-building.
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. 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.
If Google finds two identical pieces of content, whether on your own site, or on another you’re not even aware of, it will only index one of those pages. You should be aware of scraper sites, stealing your content automatically and republishing as your own. Here’s Graham Charlton’s thorough investigation on what to if your content ends up working better for somebody else.