Obviously acting requires different skills, and there are many ways ways to define what makes a good practitioner of the craft. But clearly the main thing that you want to achieve when playing a character in a theatre production is to be convincing to the audience.
Characterization aside, the main way you achieve that is through your emotional commitment to your role. If you do your preparation and work out what your character really wants in his journey throughout the play, then commit to that on a deep emotional level, you will be a compelling presence on stage. All your words and actions will seem to arise out of your character. The audience will believe you are real.
Your fellow performers will also benefit. You'll be affecting them with the power of your emotions and they are much more likely to respond in kind. If all the actors are similarly committed then it will create a self-reinforcing process that will lift the entire production. That's why the phrase "there are no small actors, only small roles" is so often quoted by directors.
On the other hand, if you aren't quite sure what you're character is trying to achieve emotionally, or know but don't make that commitment, while on stage you'll be doing everything from your head instead of your gut. You'll be merely saying your lines, rather than having them arise out of the emotions you're feeling. Rather than being in the moment, you'll be anticipating cues.
If the other actors are any good and have created a convincing world on stage then you'll seem like an impostor -- a wooden presence holding onto the furniture, whose words and actions ring hollow. You'll suck the energy out of the ensemble and could even end up ruining the whole production. In short, if you spend all your time worried about the mechanics of your performance, rather than absorbing and embodying the character's emotional journey, you will came across as false to the audience.
Now, to SEO: It may seem like a long bow to draw but each website is not unlike a role to be played in that it has qualities, characteristics, and most importantly an ultimate goal. That might be to tell people about a product or service or convince them that you're an authority in your field.
Sure, it's not an emotional one, like Stanley Kowalski in Streetcar Named Desire. But your site is going to go on a journey nonetheless. And not unlike a character in a play it doesn't exist in isolation. It will grow and accumulate content as well as interact with other sites, and on social media.
So, like the prepared and committed actor, you need to know what those intentions are for your site. Needless to say, they don't include page one rankings in search engines. They will be a welcome benefit; a result of your good work.
If you commit to your website goals and pursue them with focus, all your actions will come as a result of that. Among other things you'll add quality, relevant content and comment thoughtfully on related blogs. People who see it will be impressed by your authority. They'll share your content, link to it, etc. Google will pick up these signals and reward you accordingly.
Now, if you as a webmaster are like the bad actor who is lazy or uncommitted or both (and who is basically on stage for the glory rather than for the love of the creative process and the satisfaction of creating something compelling) you will be fixated on the mechanics of SEO. Rather than doing the things that will inevitably result in genuine social shares and backlinks, etc, you'll be thinking: how do I get those backlinks and social shares? You may even end up buying them, and in bulk. You'll be doing everything the wrong way around.
Sure, you will almost certainly get some SEO benefit, and you may even snare a couple of those page one positions you craved. But will they last? Odds are you'll be beaten in the long run by pages that were created by those more committed to quality and relevance. Like the audience rolling its eyes at the bad actor in stage, Google will ultimately deem you an impostor. Definitely an outcome you want to avoid.