Regarding internet users who express a preference for something鈥攕uch as a specific smartphone brand鈥攄o not try to change their minds; doing so is unlikely to succeed, or at the very least, extremely difficult.
Since these are matters of personal taste, what truly matters is making a difference in the world through your own perspectives and preferences; everyone has their own tastes, and it is important to respect that.
Say that it is perfectly fine for someone to hold a different opinion鈥攅ven one that contradicts yours鈥攁nd that you understand why they might feel that way about the brand in question; this allows you to avoid disagreeing with the commenter or the brand, while keeping the conversation positive.