For some people they simply stick with writers they love. I've had periods of my life where I have focused on one writer such as Steven King, Lawrence Sanders, Clive Barker and Robert J Sawyer. But I prefer to move around the genres a little more these days, but the risk is that I won't find something that works for me.
So, Ms. Homes, please don't take it personally, I'm sure a major part of the problem is me. But I think it's sensible that if I'm not enjoying my current read, I'd like to save a few hours of my life and move on. So, for me, I think it's ok to give up on a book, life's too short for reading things that isn't grabbing my attention and filling up my entertainment tank.
I find that downloading book samples is a good way to see if you will actually enjoy a book. I had a little time to spare the other day and browsed around Indigo and picked up a few books that caught my attention. I noted their titles, then that evening I did a little more research on the books at home and downloaded a sample of Time and Again by Jack Finney. I quickly got into this classic time-travel story and couldn't wait for a online order and popped back to Indigo to buy the book at full price. Loving it, review to come.