Hi- this question may have been asked previously... When getting links from "on topic" sites - how do you determine what is "on topic"? E.g:, if I sold "silk flowers" should I link only to other silk flower sites or would a site selling "vases" be considered relevant? In my mind, I think I should only link to other silk flower sites to make the relevancy 100% accurate - however, this does set up a separate problem, other sites selling silk flowers are unlikely to link to a competitor.... anyone with any views on getting links to ecommerce sites? and how relevancy rules work?
In my opinion vase sites, craft/home decor sites would be legitimate links. If the silk flower manufacturer used has a web site always ask for like from manufacturer's site.
If your focused on 100% relevancy, then it sounds like you are only worried about Google. Granted the almighty G provides some healthy traffic, they are not the only search engine. If I were to create an eCommerce site I would be more focused on getting links on sites that can provide traffic over PR relevancy. They should still be relevant, but not the the extreme that you've mentioned.