The "smashable brand" theory was developed by Danish author, and brand expert, Martin Lindstorm, who holds that the best brands are those that are smashable.
Lego is one such brand. Consider the humble Lego brick. Immediately recognisable, it's a brand icon. If you were to walk into a Lego movie by mistake there would be no doubt about the brand. It is a consistent experience in terms of visuals, tone, and even world-view. No matter how you encounter the brand, it is recognisable as a part of a bigger whole.
In the digital context, brands are smashed all the time. You see brand tweets and branded Facebook posts out of context. You scroll down the page and miss all the clever creative in the banner ads. You open a brand email, but only read the first half. People seldom get to experience the brand as a whole online.
This fragmented way of experiencing brands is problematic for both companies and consumers. Fragmented brands are ignored and forgotten. People experience a lot of clutter online - like shards of broken glass scattered in the environment - and it is off-putting.
How to tell if your brand is smashable on social media?
Consider whether your last few posts could just as well have been posted by your one of your competitors? In other words, if your brand's voice, character, purpose and community aren't coming through in a distinctive manner, then your brand is smashed, and not smashable.
You want to be visually consistent, tonally consistent, and most importantly: consistent in world-view. Lego, for example, stands for the power of productive play and the value of imagination. No matter where you encounter the brand, this is the prevailing world-view.
Examine your online advertising efforts. Is it well designed and compelling for the web, or is it just a shrunk print ad?
Level-up from being Smashed, to being Smashable.
Start paying attention to both the big picture and the details.
Big picture: What does your brand stand for, and why should people care?
Details: Is the look, voice, and feel consistent wherever people encounter the brand - every touch point, online, in-store, in-person, on Twitter, on-the-phone, the brochure and so on. All of these fragmented pieces represent you, and they should be instantly recognisable as a whole.