The most difficult part of zipper installation is making it look good. With the glue-set method you eliminate most of the challenges. The process becomes quite easy. The idea behind the glue-set zipper installation is to use adhesive to hold the zipper in place, while sewing, instead of pins. This allows you to top stitch the zipper without having to wrangle with the pins. And, since you are top stitching it into place, you have more control on how it looks on the outside, thus, more chances at zipper success.