I had no idea that even existed
You know... [url=http://www.bungie.net/en/Activity]this handy dandy thing.[/url]
For some, I feel it's an untapped feature of bungie.next that may have been ignored or users may not realize it's full potential. Once you get into the habit of checking it daily or how often you sign into bungie.net, it can make your experience much smoother IMO.
I think of it as a Facebook or Twitter feed but for bungie.net. I personally check it a few times a day, if this was available on bungie mobile it might be a problem for my over abundance of checking things on the internet.
The Activity Feed in conjunction with eliminate conversations/users through hiding/muting can work wonders. You'll never miss the conversations you really enjoy seeing by following users. How often do you use you Activity Feed Community?