I used to enjoy doing that but learned that whilst all oils have a use by date, very few have a date indicating when it was bottled (and that's the really important bit!). As oil ages you lose a lot of flavour and when tasted it gives you a greasy texture in the mouth. The oils they send me are very fresh and do not feel at all "oily" in the mouth.

I do agree though, rummaging around old family deli's in Spain and Italy etc is a wonderful pastime!