Sponsors section - some highlighted in orange, others grey...?

[salty150]

In the Sponsors section - what does it mean when a business is highlighted in orange next to their name - and others are just grey?

Thanks!

 

[InvaderJim]

The orange ones means there is a new post since your last visit. The greyed out ones haven't been posted in recently. If you look at the greyed out ones a lot of them haven't had any new posts in a while.