Distributing documents electronically through email rather than by regular mail can significantly reduce postage costs. This is especially true for larger documents. A 1996 case study found that because of shipping, producing and delivering five thousand 1,000-page documents on CD-ROM cost less than half as much as producing and delivering the documents on paper. Savings can also be significant for a lighter weight but higher volume mailing. AT&T, for example, found that paper and postage together account for 72 percent of the cost of billing their corporate customers. Online billing can reduce the costs of rendering bills dramatically. Using lighter weight paper, such as  20 lb. instead of 24 lb., can also reduce postage costs.