What is Reach?
Reach can be simply defined as the number of individuals that have seen a piece of content. This reach can be generated organically or through paid spend.
Reach vs Impressions
Although reach counts each unique view, it does not necessarily mean this is the amount of people that have seen your content. For example, in TV advertising just because the TV played an ad this does not mean you were in the room watching it. Reach simply refers to the amount of times your ad was ‘served’ and appeared on someone's screen. If an ad is seen twice or more by the same individual the reach count will remain at 1, but the impressions of that ad increases. Impressions do not count unique views, they count the total number of times your ad appeared on a screen (unique or repeated).
Reach is the estimated number of customers your content was shown to.