If your brand extension is not relevant or logical to the core brand, you risk diluting the power of each.
Derrick Daye gives fine examples. Seth Godin frames a thoughtful brand formula.
Bottom line: Stay true to your core brand and your customers will be true to you.
Note: I will be taking a very short leave from Diablogue. We’re moving out of state and we hit the road tomorrow. CU L8R.