Marketing implications of each stage of the product life cycle - details here. You need to know this.
Extension strategies extend the life of the product before it goes into decline. Try clicking on the pictures.
Advertising – try to gain a new audience or remind the current audience.
Adding value – add new features to the current product, e.g. Spy phone app on mobile phones.
Explore new markets – try selling abroad.
Advantages and disadvantages of product life cycle theory. Details here.