I would seriously suggest that you read their instructions on the website, there is a video to watch and also read the instructions that come with the nail strips. It is not super hard to use, I only messed up one strip on my first try. The nails stick really well and you are not able to move them once stuck down properly. The fronts are filed kind of under your nail and break easily.
They claim that these strips last for 14 days. I removed mine after Day 9, when a giant chunk broke off my thumb nail while I washed my hair. There were small cracks near the tops of most of my fingers and a chip on one other finger. I must say that 9 days is the longest any nail polish has ever been on my fingers, but it was not quite the 14 days promised. My nails also seemed to grow fairly fast and it would have needed to come off after 14 days if nothing had chipped simply because the nail bed would have grown out to much by then.
The application was neat, no smudges, scratches, or other imperfections; in any case, not if you managed to stick it on straight. It took about twice as long to apply than it takes me to apply nail polish, but it was MUCH neater and you did not need to worry about touching things before it was properly dry. If money was no object I would use it again, especially the intricate patterns.
You can see pictures here
http://lastexpected.blogspot.com/2012/09/incoco-nails.html