Because it is cheaper to outsource to India.
The survey company employs a company in India to use their website to collect & sort their data, then send them back the competed data. Cheaper.
I know a lot of photography companies, the ones who sort photos of events & grads, send the pictures to India to sort and categorize and tag. Then have them sent back or have India host the shots. Costs only a fraction of what it would cost in the USA & they are faster. Cheaper labor costs. cheaper server/internet costs.