The main benefit to being Dugg, especially prior to Twitter, was watching thousands of people reshare your content through blogs. These links were SEO manna from heaven, which was why gaming Digg was a cottage industry.
Even SEO seems to be a pretty terrible way of attracting new readers. Nine times out of ten, they go to your blog post, find what they were looking for, and leave.
This is a pretty common misconception among geeks. Let's say we have two sides to a business: a blog and something which isn't a blog. If there is a competent SEO in the room, links to the blog (or other linkbait) benefit the non-blog part of the business, too.
Starbucks loves getting in the New York Times for being socially conscious latte liberals who are in favor of small furry creatures, artisan coffee farmers, and other South American mammals. Is there anywhere on the page to buy coffee? No. Does it sell coffee? Yes. SEO is like that, except many orders of magnitude more efficient.
I can't upvote enough. People on HN really don't understand the true value of backlinks, and hence the value of the 'bad traffic' people who generate them.
I doubt you'll see this since the thread is old, but you aren't making a valid comparison.
You could not have realistically have 300k wives at the same time, but you could have 300k customers.
What you're saying goes completely against any type of advertising or promotional model that I am aware of. This is why there is more than just Cost Per Acquisition ad models.