No its not about classist opinion. I'll tell you how it'll go. You would probably as a way of casual conversation(in What's App or FB messenger) , mention that

No its not about classist opinion. I'll tell you how it'll go. You would probably as a way of casual conversation(in What's App or FB messenger) , mention that it would be nice if you bought an Air Conditioner. Now, normally FB won't(hopefully) read those messages because of its privacy policy. Take free basics now, they're explicitly static that they can decrypt traffic. So now that you've mentioned an Air Conditioner, FB will start showing ads the next day saying "Air Conditioners at a discounted price". You get influenced and buy it(remember, you did not impulsively go to a shop and seek to buy one, you just mentioned it as a way of casual conversation). Do you see where its going? That's one part of the problem. The rest is already summarized nicely by IIT professors.