I don't see why the majority of online resellers would be concerned by being "reduced" to "back-end order takers". That's the easy part of the business, while payment and customer support is the expensive and annoying part. Most consumers are not loyal to any one online reseller anymore, Amazon excluded perhaps.
If I was to pick where I would want to be in terms of online retail in the future, I would want to be the business with the warehouse and just supply eBay, Amazon, Google and any direct shipping customer I could find. That's where the money is in the future, at least that's what I believe.
They may have outsourced that to Amazon Fulfilment already.
I'm not talking about business threatening decisions (like relying on a free Google API, or tying your hosting to your registrar). But for most purchases at worst you will lose the money tied to it, which is probably not that big a deal.
Few weeks ago I ordered stationaries from an obscure Japanese website I had never heard about before, for my Japanese tea subscription service [1]. Total cost was around ¥4500 (~$37). I didn't hesitate, worst case I would have lost ¥4500. Turned out everything went very smoothly and I will certainly buy from them again. But maybe they have dreadful customer support, how could I know?
Next time I look for something online maybe Google will propose me a "Buy Now" button. And maybe I will give it a try, what could possibly go wrong? At worst I will lose a few bucks?
[1] Tomotcha (https://tomotcha.com)
Also, in UK google might face some legal problems with distance selling regs unless they sort out the customer support stuff.
[1] if you place fake reviews having a few like this is probably a good idea. It's much more preferable to me to see things like this than a bunch of five star great reviews.
That said, I'm only careful in proportion to the risk: why spend much time reading random reviews for a small purchase?
Especially (to go back to the subject of the thread) if it's to buy something from a big brand like Google: I'm certain to find both good and bad reviews, both fake and real. I'll just try and see by myself. Small risk for me. Huge risk for Amazon...
I haven't bothered with paypal or ebay since. Hell with them.
BTW thats another plus for Amazon, their giftcard program. Beside being able to buy them with cash in any shop one can get amazon.com giftcard on gyft.com for bitcoin and save 3% (or more if want to risk localbitcoins.com) and then go shopping on Amazon.
And I prefer the way they group all sellers under the same item and delivery charges + taxes are clearly displayed up front. None of those cringe-worthy ebay pages with HUGE FONTS and misleading delivery information.
In Germany I had very crappy Amazon customer service experience the last 2yrs. Problems with payments, fraud, washing machine delivery without taking back the old one although I had paid for that, etc. Worst was a stolen mobile phone (during delivery), where Amazon support gave wrong instructions during several interactions and then failed to cancel the attached carrier contract for months (blaming it on their system) which blocked me to get a new contract b/c I was banned for 6 months by German carriers.
In none of the cases Amazon did help in any positive way. Payments and fraud was only solved after I went to the police.
At least here Amazon support changed directions from 'happy customer' to 'cheap as possible'.
Anyways ... ... in my opinion, there is no way Google can outdo Amazon, it is not the "one click" button that makes me shop on Amazon but the great customer support who go out of their way to help you.
Google on the other hand and "support" have never belonged in the same sentence :( Seems like "providing support" to customers is to "low brow" for Google, and I am an avid google product user both hardware and software.