They always say they don't matter but loads of us don't agree. I think the company just say they are not relevant in case someone just went by the look of the lines alone without getting the smiley face.
For me, I have always found the lines were relevant. When I get a negative result, the empty circle, the lines are always faint, or not as dark as the control line. The closer I get to ovulation, the darker the lines get and when I get a positive, the smiley face, I always find the line is as dark or darker than the control line.
Good luck getting your BFP!