Thanks to an audience consisting of more than 750m users, Facebook has grown into an online advertising powerhouse despite the fact that, for many advertisers, the efficacy of advertising on the site is still something of a question mark.
But even though major brands have flocked to the world's biggest social network, and the company's ads are now a billion-dollar business, a recent survey indicates that a very small percentage of advertisers is actually "fully on board" with Facebook ads.
According to online advertising management platform Marin Software, just 6% of UK advertisers report having "well developed" Facebook campaigns. Some 42% are "experimenting" and the majority (52%) haven't run a single campaign yet.
Although this might be surprising given Facebook's prominence, it is good news for the company, as it demonstrates that it has plenty of growth potential if it can find ways to acquire more advertisers.
On this front, the company is working to make it easier for larger advertisers to buy ads at scale, as evidenced by its recent public launch of the Ads API. Facebook is also testing new ad formats, such as Comment ads, which may be better suited to a social network.
None of these things, of course, will turn Facebook ads into, say, AdWords ads. Google's advantage is that its ads typically deliver a strong level of intent, something that Facebook will probably always deliver far less of with its ads. That, along with rising ad prices, may explain why many UK advertisers haven't jumped on the Facebook bandwagon yet.
And it means that when they do, they will arguably need to be strategic, approaching Facebook ads not as an AdWords cousin, but rather as a separate beast altogether.
After all, it's easy to boost CTRs on Facebook (just add beer), but for most businesses, trying to achieve AdWords-like conversions will require a significant amount of learning and experimentation.