We make sense of a new idea by comparing it to other ideas or situations. (More info on Wikipedia: Conceptual Metaphor)
You can help people understand your message by using a literal or implied analogy through visual imagery or evocative language. This association helps people understand (difficult) concepts. For example: If your product solves some kind of problem, compare your solution with other -more familiar- situations with the same solution.
Recently I've seen some (often absolute) statements going around, generally in the line of "open source commerce platforms are a terrible idea". Now of course different solutions always have different pros and cons.
A hierarchy of evidence (or levels of evidence) is a heuristic used to rank the relative strength of results obtained from scientific research. I've created a version of this chart/pyramid applied to CRO which you can see below. It contains the options we have as optimizers and tools and methods we often use to gather data.