A while ago I talked about why branding matters
That's the basics of branding. What it didn't get into is another mistake companies make - failing to create brand differential under their branding.
Yes. Your products need to have a common branding message. But you can't make it too common. You have to make each of your products branding slightly unique from each other?
Why? Because it's always possible that one of your products will become a fuck up. Face it, mistakes happen. And you don't want a fuck up with one product to hurt other products.
Take Samsung for example.
Their overall branding for their phones is great. And the Galaxy name is great and should be used in their entire branding process, because it re-enforces the overall brand.
But... that's as much common branding as you need. Any more than that is dangerous. Which is why releasing two phones at the same time - one called a Galaxy S7 and one a Galaxy 7 Note is a super bad idea.
I just got a Galaxy S7 and people constantly ask me if I'm worried about it blowing up - because that's what happened with the Note 7 fuck up. People look astonished that the S7 is a different phone, because Samsung did not create enough branding differential between the two products.
What people remember is "Galaxy" and "7" so the problem with the Note 7 is fucking up their branding for the S7. And that's bad news given that the S7 is one of the best phones on the market but is now doomed to fail.
This is why, if you look at the poster for Rogue One, the words "Star Wars" are in very small letters under the name, rather then in the giant letters they are in for trilogy films. Disney doesn't want the general public to blow off Episode 8 if Rogue One is a stinker.
So, remember that when you are trying to market stuff. Keep some common branding elements, but find someway to separate the products in the mind of the consumer. It could save your business.