From what I have read in this forum, the consensus is that most people don't need 8 gig ram. So I experimented with having multiple pages in Safari, Adobe Pro, Mail and MS Word open this is what I typically have when I am working. In the activity monitor, it shows that anywhere from 3.60 to 3.90 of my 4 G ram is in use, unless I am misunderstanding the readout (attached). Can anyone help me understand this? I am going to buy a new MBA, to want to understand if I really do need to upgrade to 8G or not. Thanks.