Not just spacing. The sequence also matters as they serve as binding sites for enzymes that can promote or repress the expression of downstream genes. As just one (relative simple) example of how complicated genetic circuitry can be, I really enjoyed & recommend Mark Ptashne's A Genetic Switch: Phage Lambda for anyone who doesn't mind doing some slightly technical reading.
Disclaimer: not a biologist, and would be interested in hearing from someone more knowledgeble than I, both about the Ptashne book and about recommended reading.