Borrowing from its rival should help keep Facebook relevant.
The trend of major social networks borrowing key features off each other is
nothing new: the Facebook ticker that sits alongside the news feed is very Twitter-like,
while Twitter has introduced Instagram-style filters into the photo
capabilities of its mobile apps. Facebook's adoption of Twitter's hashtag
feature may ruffle a few feathers, but (like Google+) Facebook had to adopt it
eventually or risk being left behind.
The appeal of the hashtag lies in its simplicity -- it's really...