Founded Increase Media (personal marketing agency) and Dancesportlife (#1 community for ballroom dancers - 200k+) Personally helped companies create and refine their brand strategy, marketing strategy, social media strategy and ads strategy.
Defining a marketing and communication strategy for your brand and company
Spent over 10M in advertising for small and medium-sized businesses, including eCommerce, SaaS and personal brands.
Defined growth strategies for various companies, from media communities to SaaS and others.
One of my passions is working with small and medium businesses, post-product-market-fit, and find opportunities across their business and find solutions through design thinking, focused on marketing & product.
First off, Facebook's algorithm is auction-based, so there's no literal way to tell why something costs less than something else, even though they're completely identical, which is not your case.
In your case, If your CTR is higher on one of the images, that shows facebook that your audience is engaging so they're rewarding you by giving you a smaller cost per click. So that's why.