This is the 5896th most frequent Russian word.
рекламы
Advertisements.
In this sentence, "рекламы" is used in the genitive singular case to refer to the plural collection of advertisements that were visible.
Вчера я видел много рекламы по телевизору.
Yesterday I saw a lot of advertisements on the television.
Here, "рекламы" is employed in the genitive singular case to indicate the field or type of service the company is involved in.
Эта компания специализируется на создании рекламы.
This company specializes in creating advertisements.
In this instance, "рекламы" is in the genitive singular case, specifying possession or association with the strategy.