After a slow start, former senator Ferdinand Marcos Jr. topped ad spending among all candidates in December, signalling what could be the beginning of heavy spending to keep his double-digit lead in the polls.

Candidates’ ads on Facebook have so far remained small relative to their total ad spending. The popular social media platform’s ad monitoring tool does not include payments to influencers tapped to endorse candidates, however. 

It underscores the difficulty of monitoring campaign spending on the internet, which campaign finance reform advocates said would become a big challenge in the 2022 elections. 

Sen. Sherwin Gatchalian, former senator Antonio Trillanes IV, and many local politicians are top ad spenders on Facebook a year before the polls. The Commission on Elections is drafting rules to govern online campaigning.