It's absolutely a valid marketing tool, and there are many corollaries: buy a printer and it comes with ink/toner, buy a washer/dryer you get a small box of detergent and softener, buy a car you usually get a full tank of gas and a free oil change, buy a kitchen appliance you at least get a recipe booklet.
Heck back in the '70s if you opened a checking account the bank gave you a toaster! Nowdays though they give you a kick in the teeth.
So including a small memory card when you buy a camera & lens kit makes all the sense in the world. The K2000 camera/lens/flash kit is actually quite smart on Pentax' part and all it lacks to be the perfect complete DSLR starter kit is the memory card. Non-shutterbug Moms and Dads with kids wanting to get into photography should eat it up - providing Pentax Marketing doesn't miss the boat on this.