Re: Good reasons for virtual currencies.
"Someday someone will notice that online ads yield a spectacularly low return on investment."
Not really. Online ads are extremely cheap. It also allows advertisers to run many different campaigns at once targeted all over the place. Something they couldn't do with print/TV/Billboards.
Why is Coke so huge? You see the logo everywhere. What's the return from a banner on the side of a sports field? Directly, almost nothing. In aggregate, it's massive. The logo is everywhere so when you think of a soft drink, you will often think Coke (or Pepsi), but not RC Cola or the store brand. The tactic is to use every means possible to keep the name (and logo) in front of people to reinforce the association. Those cheap and easy postings help to support the more traditional print/radio/TV ads with slogans and jingles.