And before that, carrier pigeon.

The good ole days

Phone book( yellow pages)

Underground newspapers.
Street girls.
ask a cab driver.
Hotel bars, or ask the concierge.
Bars in general
"Red Light" areas i.e. Boston's Combat Zone
Word of mouth: fuck clubs, brothels.
High end playboy-type clubs.
strip clubs.

I know out here before the internet was popular a guy would open the yellow pages and call a number.
Most of the yellow page ads did not have pictures just a one or two line sentence and a number.
Or look in the back of the newspapers for the classified adult ads.
A lot of ladies would sit at the bars.I remember a family member telling me years ago they went to visit vegas back in the early 70s and they said there used to be ladies dressed up in their best dresses.
They would sit at tables that have phones and wait.

And then the reviews were written in stone on the cave walls

Even as recently as the mid-90's, the ads in the back of free weekly newspapers used to be highly entertaining.  I wasn't a hobbyist back then, but reading the classified ads could be more entertaining than the actual newspaper content.  The free weekly newspapers that are still around don't have those ads like they once did.

Back then you could buy a tabloid in most tobacco/magazine stores full of ads from different houses.  All had fake pictures and real phone #s.  You called the # for the address, arrived and got buzzed in, met the girls in a waiting room, picked one and went to a bedroom.  No mention of $$ yet.  She'd tell you to get comfortable, you'd strip, she'd return and the money was exchanged.  I found about 4 good places and just kept going back.  Cost started at $120/hr but had risen to $200 by '93.  No GFE.  Stricly CBJ/CFS, but DATY, FIV, etc.  Not like today, but still fun.

Expectations and the sense of entitlement that permeates both sides of the hobby were not really an issue before the internet.  

You paid your money and you took your chances.

Don't get me wrong, I like the idea of being able to see pictures of girls before I hire them and even being able to read about them a bit on review boards.  Sadly however, when I start reading about guys threatening providers with bad reviews and providers refusing to see guys who don't score everyone they see with a 10/10 it makes me wonder if we are really better off...