Mark Sacks is a cute boy that has the same schedule Erin has. Rosie and Mark are good friends because their families know each other. Erin starts to like Mark, especially after they work together on the Intranet Club and sit together every day at lunch. Mark ends up liking Jilly. When Erin's personal website gets posted for the whole school to read, Mark is so embarrassed that he stops talking to Erin.
Erin and Mark end up making up. They return to playing basketball together—something they enjoyed prior to the website fiasco. Mark and Erin try kissing once, but decide that they are better off as friends.
