My take on the term

I'd call it, but more literal is: "salient discussion points".

Argumentation in this sense really means "advocacy", but that does not sound right. "Favorable" on the other hand implies a flip side of "unfavorable" which misses the point, too, so "benefit highlights" is best, IMO

These are common ways to put it, and basically close cousins to Kristina's unique selling point(s) and Steffen’s unique selling proposition(s).

When a text is singing a product’s praises to the outside world, I usually translate the word Argumentation (and its common permutations such as Verkaufsargumentation and Verkaufsargument) as "advantages" or "benefits" (see gangels' response). In English advertising and marketing jargon, it's important to avoid negative associations. Consumers generally don't want to be pushed around and presented with "arguments." The word can have negative connotations and sometimes smacks of a "hard sell," which is best to avoid.

If, on the other hand, this is an in-company document (i.e., not for general consumption), you might translate it as "sales arguments," which is essentially the same thing.

In fact, third parties reviewing the product in question might even use both words: "The company has excellent sales arguments for its range of products, including some significant product advantages."

Product advantages and sales arguments are two sides of the same coin. It really depends on the target audience. In the absence of more context (I have no idea what products and/or services we are talking about here), I can only rate my confidence level as medium (3) here.

Btw, while we’re on the topic of the German use of Argumentation, here's a handy tip for translating German marketing and advertising texts. Always look to see if you can transform negative elements into positive ones—without changing the message, of course. For example, a typical German headline might be:

"Wir verkaufen nicht nur Gemüse."

Some people might translate this as “We don’t just sell vegetables,” but a more natural and effective way to put this in English would be

"We sell more than vegetables."