How do I reach international customers quickly

Now, I want to reach customers in India.
And my approach plan includes:
1. I will send promotional emails to them
2. I advertise facebook
3. I do not think I will advertise google adwords because of the hight international advertising costs.
But we still can not reach many customers.
I want to get expert advice here.

Best,

Question is extremely vague. Without more detail, there's not much anyone can help with besides linking to the https://www.blackhatworld.com/search/.