Facebook spent $1 billion to acquire Instagram last year, but now we're learning a bit more about where the company focused its other mergers and acquisitions spending.

"In 2012, we also completed other business acquisitions for total consideration of $87 million," the company said in a recent filing. The books show that Facebook spent $15 million on acquiring new net assets, but that $72 million was filed under "goodwill," which Facebook says includes "expected synergies from future growth and potential monetization opportunities" in the future. Google, by comparison, spent $1.2 billion on mergers and acquisitions last year, AllThingsD  discovered.