Tori actually did shockingly well 1st week, considering all of her singles have flopped. She did like 65-75K iirc.
Tori has a small dedicated fanbase, though. I have friends at college who love her. She was a YouTube star, appeared on Idol, and she's had a lot of good promo for her album.
And Hilary's lead single didn't even go for pop radio adds and she was coming off an 8-year break.
The song that was supposed to be the lead single went for radio adds. People knew she was making a comeback, and she did lots of promo for the album between last summer and release date (more than ATRL will give her credit for).