Its not drastically different, just many of the methods used are very much biased a certain way. A good competitive analysis will show you what is and isn't working.
There are of course some things blocking certain keywords and user access that aren't normally issues.
I would also suspect a lot of users deliberately hide prviacy so some tracking metrics and other tools may be quite inaccurate.
I did do work for a London (UK) Escort agency before, it was a very competitive niche. Got them from 90th to 13th for their main keyword in no time at all, then they cancelled services after we didn't get on to the first page a month later.