If I want to rank for a word like "cardboard", would it be as helpful to get backlinks with anchor text like "c a r d b o a r d" or, because google reads dashes like spaces: "c-a-r-d-b-o-a-r-d". I mean, would it be as helpful as just the string "cardboard"?
If cardboard is the keyword you want your site to be found by, it's probably best to go with just "cardboard" in the hyperlinks. Who's going to search for cardboard using c a r d ... or c-a-r-d...? You may want to use a longer phrase with cardboard anyways -- it's way too generic.
It's debatable but you would possible also want to mix up the anchor text with things like cardboard box. Don't use hyphens to split the letters up though.
you should go for your keyword and modifiers. So... Site name Site URL Card board Cardboard Cardboard box etc