Micro-theming is linking from a page with a keyword to another page about that same keyword or theme- except the page is located at some random or arbitrary location in the site without any thought or consideration given to Website Silo Architecture.
There is a debate about how to handle this problem once it has become compounded.
The search engines do give more weight to a page that is topically themed and hyperlink referenced within the same website. But if you continue to micro-theme without planning a Website Silo structure, your site could become an organizational nightmare when it comes to product location and visitor enhanced optimization.
It is best to plan a complete Website Silo Architecture or use a Silo-bolt-on method taught by the Theme Zoom team. Micro-theming for too long It is like putting a band-aid on a broken leg, and continuing to walk on it every day (i.e. adding keywords to the site every day). Eventually you are not going to be able to walk any more- let alone win a marathon.
Also See Theme Zoom