Ways to differentiate from competition?

What are some common and not so common methodologies to differentiate from your competition? Here are some I can think of:

• Customer service
• Returns policy
• Donating small part of revenues to charity (corporate social responsibility)
• Branding

Though the answer depends on your market, here are a few more generic differentiators:

• High quality & price - Go for ultra luxury, like luxury airlines.
• Low quality & price - Or for a low-end disruptive innovation.
• Sub-niche - Aim for a sub-niche within your overall market.
• Company culture - Create a unique company culture in your market, like what Zappos did.
• Distribution - Get your product to your customers in a different channel than your competitors, like going direct vs using resellers.
• Value chain - Make a better (or cheaper) product by changing your value chain, like what Apple did.