As a Seattlite, the impact that Amazon is having here is distinctly bad. Rents ARE rising at remarkable rates largely because Amazon has gone from 5,000 to 25,000 employees in the last 5-8 years, and they're being paid so much that they can easily afford $2k for 800sqft.
If we're to expect *another* 20,000 Ama-workers... then fuck me. Anyone paid less than $100k/year will be forced to the fringes of the city, and traffic with become so bad that we'll have to adopt J.G. Ballard's "Chronopolis" solution, where different workers use different clocks in order to mitigate rush hour (or rather, rush hour just becomes permanent, instead of total gridlock for 2-3 hrs a day).
If Amazon wants that many workers, they should build their own dormitories for them. Lord knows these pale-faced socially-inept "bro-grammers" don't really use their living spaces for anything but re-heating microwave meals and whacking off. o_O