What is the transferable core brand association that makes a successful extension possible?

In our last lesson we learnt about successful and unsuccessful category extensions for brands. The common problems exist in brand extensions are:
• Extending into a category in which the brand adds nothing but its identity (its products or services are not significantly different from current products or services in the category)
• Extending through opportunistic brand licensing without regard to impact upon the brand
• Extending into lower (and, sometimes higher) quality segments
• Not fully understanding brand benefit ownership, core values or importance

According to Peter Farquhar, successful brand extensions have three characteristics:
1. Perceptual Fit: Consumer must perceive the new item to be consistent with the parent brand.
2. Benefit Transfer: a benefit offered by the parent brand must be desired by consumers of products in the new category.
3. Competitive Leverage: the new items must stack up favorably to established items in the new category.

So, if a brand extension is build by considering the above concerns very unlikely that the brand will fail in the market place.