Willow visits Tara's grave for the first time, and she leaves a handful of stones on the gravestone. There is a Jewish tradition (Willow is Jewish) that one leaves a small stone or two on the gravestone during every visit to a loved one's grave. This tradition is also visible at the end of another Joss Whedon project, Serenity (2005), in which such stones are visible on the graves at the end of the film.
This is said to feature the first known use on television of "Google" as a verb when Willow asks, "Have you googled her yet?" and Xander responds "She's 17!"
Cassie's name is an obvious reference to the mythological Cassandra. In the world of Greek/Roman mythology, she was a seer whose visions always came true. However, after rejecting the advances of the god Apollo, he placed a curse on her that ensured that her prophesies would never be heeded. This is reflected in Cassie's various predictions, which are in time realized, regardless of the surrounding people's doubts and disbelief.
The book Cassie Newton is reading, "Slaughterhouse-Five" by Kurt Vonnegut Jr., deals with an alien race who can view the future as they travel through their lives in a non-linear time, but have no free will; much like Cassie knows what will happen but cannot change her fate.
Despite credited, Emma Caulfield Ford and Beth Skipp do not appear in this episode, as their only scene was cut. In the scene, Anya attempts to get a woman named Lulu to make a wish in revenge for her boyfriend forgetting her birthday, but accidentally ends up counselling her into forgiving him instead.