Five very different brands with very different social media marketing tactics, I'm sure you'll agree?
The great thing about taking a look at brands that have truly mastered social media (once you get past the insane envy) is that they all use techniques that can be adopted and mastered by any brand.
Yes, you can try the Nivea "search and help" and you can master the Charmin hashtag marketing campaign. All you have to do is test, analyze and refine.
The more time and effort you put into social media, the more you will get out of it.