With the end of the year fast approaching, is your staff, board and die hard supporters looking for ways to help? Tell them to donate through one of your Facebook ads because it will help your organization save money. Here’s why.

Facebook charges on a cost per one thousand impressions model (CPM). What they charge depends on how much competition there is among advertisers and the click rate of the ad. Essentially, Facebook rewards advertisers who get higher click rates by lowering your CPM. It does this because the click rate is an indication that your ad is relevant and it’s in Facebook’s interest to serve ads that are relevant.

If your ads receive a lot of clicks at the beginning of your campaign, it can go a long way to cutting down your ad costs. This is especially true for ads appearing on desktop. Desktop ads face more advertising competition than mobile ads because there are fewer people using desktops these days. This means advertisers have to compete more with each other to get fewer people’s attention. However, desktop is the platform where the overwhelming majority of donors give because it’s easier to enter their credit card info. You want to be there.

Over time, as people tend to click your ads less frequently, your click rate will go down and your ad costs will go up – but only incrementally. The initial “juice” your supporters injected into your campaign goes a long way to keeping your costs down.

We know this first hand through a Facebook campaign we ran.

Below we can see that a large number of donations came in on the first day of the campaign.

We can also see that the cost per thousand impressions went down considerably after that first day and only went up only slightly after that.

You may be wondering what the CPM would have been if we hadn’t received those initial gifts? It turns out we have an idea.

When we started the campaign we targeted desktop and mobile in one ad set. But because most of the conversions were happening on desktop, we wanted to spend more there so we split the campaign into two ad sets – one for each device.

Below are the desktop only results. As you can see very few donations came in initially.

The CPM of desktop in the original campaign had been $5.38. After we separated it out, it skyrocketed to $14.72 on day one because we lost the historical data. This is how desktop ended up performing overall in each.

So, what’s the lesson to be learned? Get your supporters to donate through your Facebook ads at the start of your campaigns. It can go a long way towards keeping your costs down. And don’t forget – separate your ad sets by device from the beginning.