The makers of Laundry Whizz considered a new promotional method for their product. A small bottle of Laundry Whizz was placed in the mailbox of college students as they came on campus in the fall. Along with the Laundry Whizz, the students received a coupon for $1.00 off their next purchase. They could receive another coupon for $3.00 off if they went online and emailed five friends at another college, telling them about Laundry Whizz. The friends could then go to a website and print a coupon for $2.00 off their next purchase. The sample bottles given to the college students are an example of , while the emails to the five friends are an example of .