Sometimes Wikipedia doesn't cover the topics you need to have defined. I think this is the case with persona as the term is understood in the online communications world. Here's my attempt to rectify that.
Persona is defined as the aspect of someone’s character that is presented to or perceived by others. The most important words in this definition are “presented to” and “perceived by.” These words convey the notion that someone’s persona is changeable depending on how the person in question chooses to present themselves to the external world. That person’s persona has multiple possible interpretations depending on who is apprehending the person in question.
In physical reality, it is possible for one person to have multiple personas. In online forums of communication, it is much easier for an individual to manipulate their persona because they are in direct control of what aspects of themselves they choose to present. In face-to-face encounters, it is difficult to change the perception of one’s gender or age and impossible to deny one’s height, weight, and other objective physical qualities. Online, it is possible to falsify any of these realities because the mode of personal interaction is largely text-based and photographic representations can be faked.
People engage with social media platforms for a diversity of reasons, ranging from narcissism to simple curiosity. While the types of social media users exist on a spectrum, they can be grouped into three broad categories: Divas, Experts, and Observers. 
“Divas” participate largely out of narcissism. They enjoy the sound of their own voice and love seeing their words in print. The quality of thought behind their social media posts is irrelevant as self-aggrandizement is their goal. Divas will post copiously and indiscriminately, using every (and any) social media platform available. Even if they have nothing to contribute to a topic of discussion, they’ll weigh in to increase the volume of their output.
“Experts” are discriminating online participants, weighing in mostly when they have something to say. They focus on topics on which they have meaningful contributions to make and are quick to credit others for their good ideas and quality input. They generally attract a large online following by establishing their various feeds as credible, worthy, positive, and respectful of others.
“Observers” are passive users of online social platforms, preferring to read the contributions of others rather than risk making their own. They may be interested in participating but lack the self-confidence to do so. In this respect, they are the lurkers of the online world.
Individuals now have access to the machinery of publishing via the World Wide Web. Where in the past it was necessary to build personal and professional reputations through job experience and interpersonal networking, it can now be achieved more directly through online self-promotion. This is referred to as personal branding, the attempt to create a desired emotional response when others hear a name, see that name online, or meet a person face-to-face. 
There are several recommended steps to managing one’s personal brand via an online persona. 
- Audit your online presence. Be aware of how you might be perceived through your online activity and records. This can include establishing Google Alerts for any online appearance of your name.
- Establish distinctiveness. If your name is a common one, consider adding a middle name or initial to differentiate yourself.
- Start a personal website that allows you to post a personal biography, a summary of your background, a list of achievements, and samples of your work. Associate with other brands that already have strong positive identities such as schools attended, companies worked for, and organizational memberships.
- Invent yourself by putting forth a strong supporting narrative for your desired persona. Everyone has a personal story. Yours should be compelling enough to be distinguished from the crowd.
The advent of the World Wide Web fostered the mediation of personal interaction via multi-player games or so-called virtual worlds like Second Life. These electronic forums obscure the identity of the participant through avatars—an edited version of the participant and a form of online persona.
Free from the restrictions of their physical appearance, race, socio-economic status, and even gender, participants may craft a persona that is dramatically different from their true selves. Changing one’s real world identity may be done as a form of self-expression, experimentation, or wish fulfillment. Despite this freedom, it’s been shown that online personas are generally crafted to resemble those that are close to the participant’s real world persona, albeit with enhanced physical attributes.  
The often unverifiable aspects of online personas can lead to fraud in the form of financial scams. Security experts warn of a new form of fraud called “virtual babies,” non-existent people who appear to have had birthdays, lived lives, taken out bank loans, and traded stocks only to have an online “death” in which their real life insurance policies are cashed in for the profit of the scammer. 
Fraud may also be perpetrated for psychological rather financial reasons. In Virtual Factitious Disorder, a scammer creates a fictitious online persona that purports to have a serious illness. They elicit sympathy and gather a following of strangers who offer emotional support to the “victim.” They may collect donations from their followers that will allow them to pay for supposed medical treatment. The perpetrator may even stage an online “death” if the fiction becomes untenable. The creator of the fake persona derives a form of emotional gratification from the attention received. 
Perpetration of scams in which people are fooled by someone misrepresenting their identity or circumstances has a history as old as human civilization. Twentieth-century examples of using technology for such purposes include prank telephone calls placed to strangers, or stories made up and used in conversations with truckers on citizen band (CB) radio.  The anonymizing aspect of the World Wide Web makes such misrepresentation simpler than ever.
A particular form of misrepresentation allows a malicious perpetrator to either create a fictitious persona for the purposes of deception, or the creation of many false personas that can be used to a perpetrator’s benefit. In a nod to the entity used by humorists in comedy routines, these false online personas are known as sockpuppets. They can be made to say whatever the creator of the persona wishes. There are two recognized forms of sockpuppet.
TYPE 1 – This is a sockpuppet which has prestige, status, or attributes that the puppet’s creator lacks. The motivation for the creation of this type of sockpuppet is to seek either authority, attention, or profit. 
TYPE 2 – These are fictitious online personas which are created to give the creator a chorus of supporters. If unable to be persuasive in their cause or opinions in an online forum, new social media accounts are created to buttress the position of the creator. His opinion suddenly appears to be carried by many, giving the illusion of an argument won.
- “What is your Online Persona?” Fluency Media. Accessed June 27, 2016
- Deckers, Erik; Lacy, Kyle. Branding Yourself: How to Use Social Media to Invent or Reinvent Yourself (Que Biz-Tech) (Kindle Locations 438-439). Pearson Education.
- Hyder, Shama. “7 Things You Can Do To Build An Awesome Personal Brand.” Forbes. Accessed June 27, 2016.
- “Identity in a Virtual World” CNN.com. Accessed June 27, 2016.
- Sifferlin, Alexandra. “What Your Online Persona Says About Who You Really Are.” Time, January 9, 2015.
- Kuchler, Hannah. “Not so Cuddly: ‘virtual Baby’ Boom Is a Source of Concern.” Financial Times, August 13, 2015.
- Montague, Jules. “Münchausen by Internet: The Sickness Bloggers Who Fake It Online.” The Guardian, April 29, 2015, sec. Society.
- “The Weird Reasons Why People Make Up False Identities on the Internet” Wired Magazine. Accessed June 27, 2016.