I've been put off a few downloads recently by the size of them. They really don't need to be so big the majority, but where they all seemed to be around 600Mb before there has been a trend upwards. Whilst I've got decent broadband speeds I still baulk at near 2Gb downloads and will sometimes not bother.
Example. Played the FIFA11 demo recent and quite enjoyed it. Decided I'd try and pick it up on one of the supermarket offers if I could find it. Remembered that PES was also out this week so thought I'd give the demo a shot first - 1.7Gb ... I didn't bother and I bought FIFA today. WTF are they doing with 1.7Gb for a football demo? Severe padding with HD video I'm guessing.