I found this a really interesting read and also a great question.
Kayak have got some great points on knowing your platform your posting on, applies to both whether you're advertising or generally posting, yet I think advertising on social, if done in the right way, doesn't need to stick out like a sore thumb.
Good to see Kayak commenting that brands should look to use these type of ads to also drive engagement in communities - definitely vital for a strong social presence but even if that happens, you may still need the occasional ad to jog people's memory your brand is around.
What are you thoughts, particularly on the theory that big brands do it better due to bigger budgets?
Although we're generally against social media advertising, it’s worth noting there is one exception to the rule: bigger businesses with established brands can get away with promoting their products and ideas through ads and sponsored posts. It’s because they already have throngs of established fans. They aren’t trying to find followers, but to energize their existing supporters and stay on the tops of their minds. They are using social channels to reinforce their brands as one more point of contact amongst many others.