In this photo, you see the poor old man with 3 yellowpages/directories.. So why the hell would he need so many of them?
‘Why did the directory man give you 3 phonebooks?’
‘Because we have 3 telephones.’
So, yes, it appears that in this country, phone directories are given out based on the number of phones you have.. 3 telephones in a house would get 3 directories, so imagine the offices that have 50 phones!?