Great article from Easy living the hard way on how long seeds are good for. If you like to buy organic heirloom seeds to grow your herbs and vegetables from you know that organically grown can become expensive if you buy all new seeds every year for the garden.
As I learned from this article you may not need to buy all of them every year. Some of the seeds are viable for a few years. Some as long as 5 years but others only for 1 year.
If you learn how to save your own seeds and then date and add the viable period to the packets you will be able to know which year you need to save seeds for certain vegetables as their viability runs out on the stored seeds. This way once you have some for each veggie you like to grow, you can plan ahead to save seeds to replace what you are going to need.