There was a time when pollsters went door to door to figure out what people were thinking. Gallup did that for almost 50 years, before switching mostly to telephones by the mid-’80s. Phone polling was cheaper but still reliable. That is, until the cellphone came along. Marketplace’s Lily Jamali...

If you drive 45 miles north of Little Rock, Arkansas, you’ll come across a facility packed with thousands of computers trying to “mine” the next bitcoin. The popular cryptocurrency’s value recently shot past $60,000 per bitcoin. Mining those bitcoins is a lucrative operation, and several crypto...