I have both the orange and blue, just for a change of color now and then. I put the strip right above the row on the chart I am on and it keeps my eyes on that row. One piece of tape has lasted for over 150 rows chart A 3times, chart B 3times, chart C 2times ..etc and is still sticking to the plastic holder my pattern is in. I have used the magnets in the past, and they can move too easily if you bump them. The tape stays put. Plus it is just easier, and the colors! - we knitters love our colors!
With reading charts and saying focused.I cross out the line I finish and put this highlighter tape on the row above the line I'm doing. Keeps me focused on just the line I need. One piece lasted me the 40 rows I was knitting.