In my experience of DVD postal rentals, whichever company it is (I tried just about all of them), they give you a great service during your free trial and for a month or two thereafter, sending you your top choices and with same day turnaround. Then you start getting titles off your third or fourth pages and dvRAB sent back are logged back a day later than before and/or as awaiting 'allocation' of a new rental for 48 hours, which all slows down the turnaround and reduces your value-for-money. It is said the best thing for a consumer to do is keep swapping membership between the biggies, and I'd be inclined to agree.
My own personal experience of Lovefilm was terrible. They took over my membership of Screenselect who they bought out and the excellent service I'd enjoyed for 2 years became diabolical. It also became difficult to cancel, it could not be done online (as with other companies) and I had to spend ages trying to get through to a foreign Customer Service line who then tried to persuade me to stay. I was relieved they did not pull the Lovefilm stunt of claiming my last DVRAB had not been received back, in which case they charge for their replacement cost.
I'm sure they are good for some people, but I'd recommend anyone read the reviews at the site below before considering them, or be very careful that you return your final dvRAB by recorded post in good time if you do try them (and always return early, as with all of these, Blockbuster too, they'll try and charge another month's rental if you don't, claiming they didn't get them back in time, and clear out your account list so they cannot send others - even if they'll then complain you have nothing there and must maintain a list).
Since leaving Lovefilm they have tried to tempt me back with up to 3 month's free rentals. I left 2 years ago and I still get them, one came this week. But even if they gave me a year I would not be interested, they'd be my last choice and are one of the worst examples of a monopoly and mergers disaster I can personally think of.
What I now do is buy dvRAB second hand off eBay, there's far less hassle and I'm sure it ultimately works out cheaper!
http://www.dvdrr.com/reviews/LoveFilm.html