I am super excited that Google and Amazon have entered the domain business!
The future is bright.
The future is brighter for Amazon than it is for domain investors.
The reason why Amazon is entering this field is because of the profit margins being very high. One domain costs them $00.10-$1, and they'll charge customers the market price you see today ($20-$100?)... So, for them, it's a very easy and lucrative business to enter, and for them to do well in.
As for domainers and domain investors, I am still not convinced of a lucrative future for such a group. As ICANN reported, over 1300 new gTLDS will be released in the short-term period. Economics 101 teaches us that an increase in supply will drive the market prices down. In short, don't expect to do so well. I would personally think that about 1% of domain investors will reap something significant.
Sorry to sound so pessimistic, but it's the truth. If you want to create real value, real benefits for society, and something significant over the long-term, you need to create it yourself. Instead of buying domains and doing nothing, hoping one day, one person comes by to buy your name, you can instead create value under that domain (which you already see perceived value in). Take the domain, and create content under that name. Do this for all of the domains you own. You'll learn something, provide something for society, and thus, both parties will benefit in the long run. Domain investors are not really investors. Maybe less than 1% can be considered investors. Everything else is based on speculation.
I am interested on reading research papers on the future economics of tlds and gTLDs, if anyone here has access to any. I couldn't find any. These would be great places to really understand the domain market.