[shrughes]

On notebooks they let you save battery life by not using the discrete graphics at all for a larger proportion of desktop graphics activity. On desktops and notebooks they make the graphics not completely suck without having to have a separate GPU, making low-end computers be cheaper.

[rmk2]

On top of that, they are better for thermal management on notebooks.

Now, I might be a bit bitter because I had two different nvidia chips in two different laptops die on my a grand total of 4 times, all due to faults on nvidia's part, accentuated by not-ideal thermal design in either laptop. That led to my decision that no matter what, my next notebook (whenever/whatever that will be...) will not have a discrete GPU, but will use chipset graphics. At least there, only one thermal source has to be dealt with and Intel will hopefully produce reasonable specs for that.