How long do fresh flowers last?

One of the issues that consumers have with fresh flowers is that of longevity. Everyone wants their flowers to last a long time.  I get it.  When you spend a pretty penny on something beautiful you want it to be around for a while.  Something you may not know is that there is a trade-off when you choose for longevity (sometimes several trade-offs).  Most flowers are cut before they are fully mature so the buyer gets to witness the unfolding of the bloom as part of the experience (and get longer vase life in the process).  If you let a flower mature in the ground or cut it only after it's fully open, it usually grows substantially larger than that same bloom cut three days prior.  So one trade-off for vase life is size.  
Size doesn't matter, you say?  Well, another trade-off for vase-life is fragrance.  At least in roses this is an issue.  Modern roses (especially the "florist roses") have been bred for longer vase life at the expense of fragrance. 
When I make an arrangement I try and include some big fully open WOW flowers (that will fade first) as well as a few that will slowly open in the vase.  As the first flowers fade, I would hope the recipient of the flowers will pull those to let the newly unfolding flowers take center stage.  The arrangements are meant to evolve and grow.  It's my way of bringing the beauty and ephemerality of the growing season and the life of the flower into focus.  When we tune in to the cycles of nature (which not only include, but absolutely depend on, cycles of decay) we need to make room for the whole picture.  Flowers are ephemeral.  That's part of their beauty.  It's also part of ours.  When we embrace all the cycles (and not just the young and sparkly bits) we get a more full experience of being alive.  
The above photos show tulips at the stage they *should* be cut (for longevity).  The right shows the same varieties fully open.  I love them both!