Part of providing value is building trust. Don’t link to things that aren’t of good quality or people won’t trust your recommendations. The other part of making an audience is consistency. It matters less how often you post than how consistently. If you only have time to do one post a month, that post should come out on the same date and time each month.
You brought some awesome examples. One of the best ways to get your campaign off the ground is by starting with the ideal audience. I find that I can use data to find my top customers and then make those into ambassadors, nurture those relationships, to create an epic viral campaign. Gilles de Clerck, founder of the Growth Revolution, talks about it here - https://sharesomefriends.com/blog/referral-marketing/
Apple maintains it’s viral appeal, with the iPhone X through their launch of the "Selfies on iPhone X" campaign. The secret to this example of viral marketing (which has clocked up over millions views both online and offline) is very simple: a product so great that it turns people into fans of the brand all on its own. People love themselves. If they have the possibility of spreading this love digitally through selfies, it’s almost a guaranteed win. The iPhone X’s brilliant selfie feature spread virally through various media forms before apple repurposed the viral content into one masterpiece, the iPhone X selfies film. As one of the YouTube comments says, “It’s the most beautiful thing I’ve ever seen”… This viral marketing through video has allowed Apple to spread key features such as their Portrait Lighting effects and their TrueDepth camera.