Once the decision to purchase is made, 78 percent of the
participants said they wanted to use the product right
away and therefore choose to immediately download the
software. When purchasing CD-ROM versions, specifically,
46 percent requested delivery within a few days.
they don't mention sample size and perhaps have an agenda.
The plural of anecdote is not data indeed, and what was provided was anecdotal evidence. However, was there any evidence provided to the contrary (users do buy software on CD)? I think the reason the anecdote was upvoted was due to the lack of supporting evidence for the contrary conclusion. I'll give you games and movies (although Steam seems to be making great inroads toward making CD games obsolete), but I sincerely doubt that the majority of Mac software is purchased on CD and not through the internet.
Edit: Truly confused about the downvotes (and upvotes for parent). Since when is anecdotal evidence a good supporting argument in a discussion on HN?