Until we see a measurable, provable change from one of these "social media" campaigns, they don't mean shit.
The Internet's attention span is 45 seconds on a good day, and that's not enough time to affect real change. Until this changes companies realize that all they have to do is weather the (brief) shitstorm until people move on to the next buzzworthy thing and then they can just go back to business as usual.
How many people know that the drug Martin Shkreli jacked the price on is still that same price long after he left the company? They never even did a show of putting it back briefly, the price was jacked up, Martin took the hate off the drug company that did it, and they kept collecting the money.
I don't think social media can affect real societal change because it's like trying to get an unmedicated ADD kid to do his homework, you can't hold his attention long enough to make meaningful progress.