Of course, Jackson admits, there are exceptions to every rule. It's not always a good idea for SEOers to repeat metadata descriptions and H1 tags for product descriptions, for example, but these days it's often done. In another common practice of late, sites share editorial content and product descriptions. Some experts suggest avoiding duplicate page titles at all costs. Jackson offers suggestions on how to avoid being ousted by Google, Microsoft and Yahoo if you have to smooth a few wrinkles after doing some of the things you shouldn't do.