It did strike me as odd while researching this that they spent so much time getting around ad blockers when they own the ad server as well as the content..
They could leverage the kind of stuff Facebook does already by serving the ads as regular content.
It actually used to (maybe still does) signal routing information[1]. An example from the RFC is "@ONE,@TWO:JOE@THREE"
[1]: https://tools.ietf.org/html/rfc821
You have to do a bit more yourself in BigQuery. (Define a schema and do a schema update when you log something new.) I implemented logging via App Engine requests which save the data to BigQuery. Not sure if that's better or worse than using the StackDriver service, but it's working.
Because they used the word Stack in their name? StackLead and StackOverflow seem sufficiently different to me to not be confusing. The use of the word stack is fairly common in other companies and projects like saltstack, openstack, stackmedia, etc.
StackOverflow also provides job-finding/head-hunting services, and yes, they could probably successfully argue that they have ownership of "the Stack name" with regards to the space of job placement, given they've exercised that name into many variants of Stack*.
StackLead isn't providing job-finding/head-huntiong services though, from my reading of their site they are more suited to sales lead management.
A quick search of USPTO shows plenty of other companies using stack in their registered trademarks. The search results don't appear to be linkable but starting here -> http://tmsearch.uspto.gov/ it shouldn't be too hard to find plenty.
ag is not available as a package on debian stable. Ack is though; as ack-grep. So if you don't want to mess with CPAN that's fine. The non-CPAN instructions are right on the website.
That would be a better title than "Learn Perl by experiment" or "perl-by-example" or "A Guide to Perl: By Experiment"
all of which suggest a tutorial, which you're saying is not what you're trying to present.
They could leverage the kind of stuff Facebook does already by serving the ads as regular content.