Decades ago, the famous baseball player Yogi Berra, known for his paradoxical utterings, explained why he no longer went to a famous restaurant this way: "Nobody goes there anymore; it's too crowded." 

You could make the same observation about some segments of commercial real estate these days. The rush to such sectors as industrial and multifamily has compressed cap rates, leaving many to reconsider how they measure value and leaning more toward internal rate of return.

With interest rates still low, a lot of capital continuing to pour in due to poor returns in traditional fixed income, and rising rents, there's still money to be made. But it's harder as time goes on and cap rates continue to fall. Some professionals have moved to primarily consider internal rates of return to justify investments.