I think I managed to get 3 discs out of Blockbuster in 2 weeks, and one of those was unplayable and had to be returned. Come Wed of the second week of the trial, I took everything off my list as I didn't want them doing a LoveFilm and sending me out discs on the last day of my free trial so they could charge me a full month.
If you have to return a damaged disc, Blockbuster won't send you anything else from your list. If you're on a 2 discs at home package, and they send you a duff disc, you'll be on a 1 disc at home package for a week, while still paying for the 2 disc package.
So, if you receive a disc in the post in the morning, settle down in the evening to watch it, find it doesn't play, and return it the next day, you'll lose 4 or 5 days of your paid for package just trying to get BB to send you a playable copy of a film you've ordered.
Day 1 (Monday) - Order disc on website
Day 2 - BB send disc
Day 3 - You get disc if you're lucky, although day 4 is more likely given my experience
Day 4 - Return faulty disc
Day 5 - If lucky, BB receive faulty disc
Day 6 - BB send replacement.
Day 7 - Sunday, no post.
Day 8 - Receive replacement if lucky.
8 days to get one film. No thanks.
I'm not saying the above won't apply to LoveFilm, but I found BB's turnaround times to be like watching paint dry.