This is the 3201st most frequent Russian word.
народу
"To the people" or "of the people" (dative or genitive singular of "народ").
The word 'народу' is used here in its genitive singular form in a colloquial sense to mean 'people' collectively.
На площади собралось много народу.
A lot of people gathered in the square.
Here, 'народу' is in the dative singular, referring to 'the people' or 'a population' as a group.
Для народу эта мера оказалась полезной.
For the people, this measure turned out to be useful.
In this sentence, 'народу' is dative singular, indicating possession or relevance to people collectively.