Over the past decade, political advertising via social media has grown rapidly, spurred by microtargeting, which looks to deliver specific messages to tightly defined audiences. Microtargeting strategies have been claimed to be effective, but questions remain around their cost, when looking to optimise impressions for a given budget. We analyse 11,837 ads aired on Snapchat over a two-year period leading up to the 2020 presidential election in the United States, which differ in the number of targeting criteria applied. We compare the number of impressions and the spend per ad placement (measured in CPM), whilst also considering the length of advertising schedule. We find that using fewer targeting criteria and longer schedules increases impressions with comparable or lower spend than microtargeting. These findings are in line with those from traditional broadcast media, such as TV, highlighting the relevance of existing media scheduling knowledge from traditional platforms for political advertising on newer, digital media.