I mean look great from a visual, UI perspective and look great from a user experience perspective, letting someone go all the way through and accomplish their task in an easy, fulfilling way on every device, at every speed, and make it secure too. Security critically important. HTTPS is not the only thing, but it is a big part of what Google cares about right now, and HTTPS was a big focus in 2016 and 2017. It will certainly continue to be a focus for Google in 2018.
The amplification and link building is always going to be difficult in a space where all related sites are potential competitors. Take for example a website focusing on news for a particular sport. Sure, you might get forums links, social media links, and other lower quality 'no-follow' links, but then but no news outlets, sports clubs, and the like would be interested in linking to your content because they have their own sports journalists. Likewise, fan sites, and others would be more inclined to link to well established traditional media, instead of your 20k per month visitor sports site.
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.