Purchased one based on a recommendation and was told herbs can last up to 8 weeks yes, eight weeks. Parsley is at 6 weeks and counting.  Most amazing though is that the cilantro, which generally lasts about 5-8 days before it starts to go off, is going strong after 5 weeks!  
Ordered another one 3 actually, will gift to a couple of friends who cook when I realized I can keep more herbs on hand without worrying about them spoiling before I can use them.  I'tl pay for itself very quickly.
Why didn't I know about this sooner?!?!?