My answer this question is you have to use quora. Answer peoples question. Most of the quora traffic is indian and they are giving it free as long as you have good answers in your niche. For my 10 answers i have received 9.5k views on my answer. Use instagram as most of adults and teenagers using this. Follow unfollow there you will get many people follow you back and send them to your offer by direct messaging to your new follower. Use Facebook groups they are highly engaged these days. I received 885 likes on my post within 8 hours. But you need to find right groups and their engagement rate. Join 10-15 of them boom you will drive hundreds of visitors everyday. Do Facebook ads related to your amazon products. Facebook gives cheap cost per click to India compared to other countries.