Actually, it's more likely because 80+% of Google users couldn't (and probably still can't) tell the difference between the advertisements and the results:
This is absolutely true. The background colour is slightly different, but on my laptop screen that's hardly visible at all, unless I tilt the screen at an extreme angle[1].
I have to say I kind of feel cheated by that trickery, every time, and it is one of the reasons (though not the most important one) that I use Google much less recently (in favour of DDG).
[1] no I'm not particularly happy about this screen, the rest of the machine is great but if I had known it would be this bad I might have picked a different model (I got an Asus EEE 1215B)
I've seen pages where the Text Ads have the same Style as the overall page. The only thing that sets the Ad apart is a small grey text 'Ads' or the like.
I've may have seen far more of such pages. But obviously i can't tell since they're near-impossible to spot the Ads.
The trend is keeping things "by the book" from search engines point of view, And manipulate humans in subtle ways
by confusing contents and ads.
I think that my comment still applies. We've gone from a smaller number of people with a high concentration of those that are 'tech literate,' to a larger number of people with a smaller concentration of the 'tech literate.'
That's probably some of it. I could be wrong but I think the ratios have gone up more than that. Anyway, I don't think the "techies don't click ads" effect is really as strong as a lot of people assume.
My guess is that (a) Google has optimized the ads for more clicks (b) advertisers have gotten beter at attracting clicks & (c) People are more aware of when to click on ads. If you're looking for a babysitter, you are more likely to have one booked ten minutes from now if you click an ad than an organic result. People have, consciously or unconsciously become aware of that and they click the ads when they want that kind of content.
> I don't think the "techies don't click ads" effect is really as strong as a lot of people assume.
I kind of doubt that myself and would like to see some numbers before coming to that conclusion. Especially if just talking about CTR instead of conversion rate. For the latter I'm willing to believe that if the techie clicks the ad, they're more likely to buy. Though that is a guess I'd also like to see supported with numbers :)
It might also be very different in the USA. If I see an ad with my search results, a lot of the time it's a US company and even if I would want to use a service on the other side of the ocean, I can only pay with either my creditcard or PayPal. I won't use PayPal and my creditcard is tucked away in some drawer somewhere. Actually, for any non-Dutch company (say, German), a creditcard or PayPal is usually the only option. On a Dutch site I can pay with iDeal via my bank card (zero transaction costs, authentication via text message on my banking account's site).
