alt Hacker News> I am wearing a T-shirt right now in fact that was advertised to me a week or two ago as "on sale" for £8 (eight) and which I clicked through and purchased.
This means the ad was effective. But was it useful to you? Did it save you from having to look for it yourself?
If you were not thinking something like "I need a certain T-shirt" before this came up, it's likely the ad created a desire in your mind which you didn't have. You got manipulated successfully by the advertiser.
I think what was left out of the blog post was "helpful to the advertiser".
The meta point is that advertising has become so ingrained into society it really is difficult to differentiate if a need or desire originated intrinsic or externally. It's really great for companies selling stuff.