The more you are able to show the impact your donor is making, the more donations you will get - that is the purpose of the Impact Metric feature.
The impact metric is a counter that automatically shows how many units of impact your fundraising campaign has created.
Here is an example:

Let’s say that your unit of impact is $15 and that it provides 1 week of food to a child. For every $15 you get in donations, then the impact metric counter will show 1 more week of food provided. If you have $60 donations, the it will show 4 weeks of food provided.
To set up the impact metric, follow the steps below:
Set Up The Impact Metric
Step 1: Under Campaigns, select your campaign Settings (gear icon) of the campaign you wish to edit.

Step 2: Under Fundraising Website, select Impact Metric.

Step 3: Enter the following Impact Metric settings:
Turn on Display Impact Metric (toggle to blue)
Metric value
Metric description
Note: Try matching the Impact Metric Description to your Donation Tiers.

Step 4: Save in the lower right hand corner.
Additional Information
You can only have one Impact Metric per campaign.
The calculation of your impact metric is automatically done on your CauseVox fundraising site.