Re: .05% -- I personally think mentioning GPD is useful because .05% sounds fairly trivial, but .05% of the GPD is still something like eight billion dollars, which is a very non-trivial amount.
Finally, I really like the philosophy of the blog post you linked to, but I think it's talking about a slightly different point. The examples I gave are about a single organization doing something that saves an aggregate of millions of hours or millions of dollars; they are not about trying to convince millions of individuals make a conscious choice to each save one dollar or a few minutes. In the language of the linked post, I would consider the latter to be a million minnows while the former is a single shark.
Previously, people might have a book or a discman on them but many people had nothing and were simply sitting bored. Now, they're at least at 50% productivity if not more.
The smartphone alone eliminates half of the losses that the DMV has caused.
And say you take a half day off to visit the DMV your in 95% of the cases not going to get more or less things done that week - unless your a piece worker on a production line which for HN readers is probably zero
It's an annoying, emotional statistic, used in the same way that my cereal box tells me they've saved 30 lorry-loads of cardboard from being produced. In the context of the millions lorry-loads of rubbish generated, it's not important.
I also dislike the 0.05% statistic (which is essentially saying Americans spend 0.05% of their time queueing at the DMV) as it's uselessly emphasized with "a significant amount considering the size of the GDP".
If everyone does a little, we’ll achieve only a little. David MacKay http://www.withouthotair.com/c19/page_114.shtml