Keyword Injection aka Page Customization SEO

Hello Fellow Warriors,

I have a quick question about keyword injection (aka page customization) for SEO. Now before you give the yay or ney, please take a sec to read the whole question.

So we know that keyword injection is bad for SEO. Having said that, it's clear that many sites use page customization which, as I understand (please correct me if I'm wrong), is just keyword injection in the proper context.

Let's take a simple example. Say "American cheese" and "yellow cheese" and "yellow cheese square sliced" are all talking about the very same identical product.

Now let's say that to rank for this you need to write a 3600 word article (because the competition is there).

Okay, you do it for American Cheese... now what?

We write another 3600 totally original and unrelated article about "yellow cheese" know that it's basically the very same product? Then repeat the same for "yellow cheese square sliced"?

Doesn't seem logical. (Links not permitted - removed by mod)

Just to be clear... I am NOT talking here about trying to game the system and dynamically injecting "concrete" instead of "American cheese". Just situations that warrant the dynamic injection because the subject, while the same, it's being addresses with different keywords by the end consumer.

Can anyone share how to go about doing this without problems. I am aware of canonical tags but I wanted to know if some experienced marketers have any Do's and Don'ts when it comes to this subject. Also, what were the results. How many of those pages ranked - besides the main one?

Thank you