Ask HN: What are some new growing industries?

What are some new growing industries with low start-up costs?

I've been reading 'How To Get Rich' and it brought up something I hadn't thought of before: "As a general rule of thumb, then growing industries with relatively low start-up costs offer more opportunities for those who want to get rich than declining industries, or those that require huge start-up investment."

EDIT: How does one go about finding out what the growing industries/sectors are, and knowing which source to trust?