While there are a large number of American companies with their subsidiaries in India, the salaries that they pay are adjusted to the local cost of living and can be quite low compared to their American counterparts. Just to give you an example median salary for software engineers in United States is US $100,000 per year while in India is only $8,000 per year.
Why work for a US company directly?
When you work for an Indian staffing company who has a US based client or a US company with an office in India, they tend to pay lower salaries because of them acting as middlemen or paying relative to the cost of living.
If you work for a US company directly, you are able to but also by removing the middlemen (staffing agents/subsidiaries) you can ask for a
Higher salaries
This would be