I've been using vistaprint.ca for many years to print things like business cards and thank-you cards and posters and postcards and what have you. I'm generally very happy with them; my products look great, they arrive in time, and the price is reasonable. But now they've just made me love them. I had a special item that I designed and ordered. They emailed me a day after receiving my order to say they'd noticed some of the words (my entire second line of text) was difficult to read because the font was too small. They had fixed the issue and prepared a proof for me to review if I decided to go with their replacement design - at no extra cost to me. I could also stick with my design if I chose.
I reviewed and approved their design, and thanked them for saving me from myself. It wasn't a huge order, and it would not have been a lot of money wasted (about $50), but I very much appreciate how they took the time and bother to ensure my products look good.