Reach

TL;DR

Reach refers to the number of people who see an ad or a campaign.

What is the reach as a metric? 

Reach, as a metric, refers to the estimated number of people it is possible to reach through advertising channels, or any promotional campaigns.

What is the difference between reach and impressions?

While the reach represents the number of people who have seen an ad or a piece of content in a campaign, the impressions refer to the number of times the content itself was seen. 
To make it easier to understand, if a website runs an ad, and it was seen by 1000 people, then the reach is 1000. But if the ad was displayed 5000 times, then the impressions will be 5000, since a person can see the same ad multiple times.

Why is the reach important? 

All metrics play a huge role in website and campaigns' analysis, so here's why is the reach essential to track:

• Knowing the number of people who have seen a piece of content helps the business owners figure out if there is a need for optimization. To be more specific, if an ad is seen by a large number of people, but the conversion rate is low, then the content could be optimized for more engaging content. Or for a different audience.
• If the reach is high, it shows the success of a piece of content or ad and increases its chances to interact with or to be shared across the web.

Reach can fall into multiple categories on multiple distribution channels; here are some mediums that provide the reach of a piece of content or ad:

• Facebook reach, which can be organic, paid or viral; 
• Facebook Ad Reach;
• Twitter reach;
• Instagram Reach;
• Google Ads reach;
• Youtube Channel analytics > Reach