An example would be if your niche is DIY (doing it yourself) repurposing furniture, there might be a trend within the niche of redoing garbage finds found on the street into usable furniture and decor.
You obviously want people to spread the word about your brand but in order to do that you need to give them something to talk about. Updating your website frequently gives people something to talk about.
Responsive design allows your website to be viewed, used, and enjoyed regardless of the device being used. It doesn’t mean that your site will look exactly the same on each device – it’s even better than that.