Bill & Melinda have been very active on media in last one month since their 10 tough questions blog post. They are all over the social media with bunch of spons

Bill & Melinda have been very active on media in last one month since their 10 tough questions blog post. They are all over the social media with bunch of sponsored/promoted posts on FB/Instagram. And now this Reddit AMA, I am not sure what's the reason behind it but they have stepped up their social media game. There has to be a solid reason behind this uptick. Wonder why?