Fundraising depends on reaching people with the right message at the right time.
Seasonality has long been understood to impact giving because people have different demands on their attention and resources at different times of the year. But not all conventional fundraising counsel directly corresponds to fundraising on Facebook.
Fundraising via broadcasting, paper mail, or email have a fundamental factor in common, a message is being sent to a fixed audience whether they are engaged at that moment or not. If the timing is poor, then few people will see or respond to the message.
Facebook fundraising is different. Messages are only delivered to people who are active at the moment of delivery. A fixed budget will have the message sent to a certain number of active users. There is essentially no waste. Day or night, peak season or off season, only active users see your message.
It is true that users’ inclination to give will fluctuate, but users come from so many walks of life, so many schedules, and so many backgrounds that these fluctuations can be minimized to a degree. And there is a great equalizer: supply and demand.
Advertising demand diminishes in off-seasons and times; when this occurs, the cost per impression also decreases. So, while it may be more difficult to obtain donations during off times and seasons, the cost to advertise may decrease, which can improve overall fundraising outcomes.
Summer is often seen as a poor time to fundraise because people are engaged in vacations and traveling. But because of this very reason, the cost to advertise tends to decrease as well, which can make fundraising campaigns just as effective as at better times. Likewise, Q4 is often seem as the best time to fundraise, but due to increased competition the cost to advertise increases and can sometimes offset an increase in performance.
The bottom line is you should not allow blanket understandings of seasonality to impact decisions or expectations for Facebook advertising. Seasonality may well affect your campaigns, for good or otherwise, but it will not be for the same reasons that other media are impacted. The best thing to do is test in all seasons and months and scale up when performance is good and test more when performance is down.