Is there a reason folks use Yammer over IRC? My company pays for Yammer, but nobody seems to use it. Most folks (at least in the engineering/sysadmin circles

Is there a reason folks use Yammer over IRC? My company pays for Yammer, but nobody seems to use it. Most folks (at least in the engineering/sysadmin circles I tend to work in) hang out on the internal IRC server all day.