Ask Is it true that paid ads stop working as well once a market becomes saturated?

[Dominic87]

When many businesses in the same market start running ads, competition for attention naturally increases, and this can push up costs while reducing results. Users see so many similar ads that they may start ignoring them completely. Some businesses respond by changing their message or targeting a smaller audience to stand out again. Others simply accept lower returns and continue anyway. This makes ad performance harder to predict once many competitors enter the same space. Does market saturation really reduce how well paid ads perform over time?