Even though teens account for only 3% of online sales right now, they can be very influential on overall household buying, and teens have still spent $3 bln online in 2006, Jupiter Research says. Of teens who make purchases online, 83% still make purchases with their parents present, via their parents’ credit or debit card. However, alternative methods of payment, such as PayPal and gift certificates, have grown in popularity and allow teens to make purchases by themselves.