On the product's actual merits using pertinent criteria! There are other metrics you can use to judge something's quality than just appealing to popularity or engaging in pissing contests. These metrics will vary based on the type of product (e.g., food, furniture, clothing, electronics, software, media, etc.). As a metric popularity tends to be a misleading indicator regarding a product's overall quality - i.e., "the mob can't be wrong" - which is why appealing to a product's popularity is
fallacious, bad reasoning when it comes to discussing a product's quality.