A branding client of mine has been producing a lot of social content using the designs I created. It's great to see it all in action. They've gone off-piste with the supporting text they're using, which is fine, the type they've chosen fits well enough.
It did have me thinking about how typefaces (or fonts, the two are usually described synonymously, unless you're a pedant, like me) do a lot of heavy lifting.
For example, you wouldn't expect to see Comic Sans in a logo for a bank. You wouldn't expect it on the paperwork you receive from them. It wouldn't look professional, you might not trust that it's from your bank at all.
The typefaces a brand uses should be measured and purposeful choices.
A company might have multiple type elements, perhaps on the logo as well as the supporting type they chose in advertising and maybe another on their website. All three might be different. Car firm Fiat have very tall art deco style letters on their logo, use different fonts for adverts on their car ranges and another font (Open Sans) on the website.
Despite all three being different, they support the work of the brand and none fight against the visual direction.
Microsoft pulls this off differently. Using a single family of fonts called Segoe for all of their adverts, on their websites and for the text in the logo.
Not everyone has the budget to commission a fully custom-type family for their brand like Microsoft!
As my client above can attest, there's rarely only one font that's "correct", many could work. When developing a brand it's often down to having the experience to know what's good, selecting the best fonts for the job and explaining why that is.