Jeremy gave a great answer as the use of foam rollers pertains to self-myofascial release which certainly is a valid technique.
I use foam rollers within the parameters of the MELT techniques, and while the goals are similar, the approach is different.
In MELT, people assess their bodies first and then use certain lengthening techniques to improve the alignment. The techniques go well beyond foam rolling in the SMR sense and usually start with the diaphragm and the lengthening of myofascial lines as well described by Thomas Myers in ‘Anatomy Trains’.
The way I explain is to my clients and students is in comparison with a car. Before you load the car, you at least make sure that the tires are balanced and that structure of the car is sound. A new paint job, however, is unimportant.