Everyone who at least couple of times googled for anything Go related knows this site. Should I post golang.org now, because there may be someone living under a rock?
I've been programming in Go for a few years now and I've never seen this site before.
It's quite possible that the specific search terms you use (eg I never include "example" when Googling about Go[1]) and Google's personalisation (eg favouring resources you've used previously) would result in different search results to what other people might receive.
[1] Since any resource offering help in programming will include example source code, I always considered the search term "example" to be redundant.
Result #5 on a query that generic is quite far down when you consider that all of the top 4 results would equally answer the question. So many people might not get as far as gobyexample.com using your search term example.
Plus on queries that generic, a lot of people might just go straight to golang.org and re-read their docs.
Obviously this isn't the case for everyone, but it would explain why I've personally never heard of gobyexample.com before.