Is using screen unlock pattern feature a good option for login on mobile web

trying to come up with way(s) to reduce the users' drop off rate on mobile login/registration on a mobile web ecommerce site.

1 method i think could work and would like to probably test would be a web version of the screen unlock pattern feature used on phones. http://ignitersworld.com/lab/patternLock.html

Compared to passwords they are easier to remember and already being used by most users.

Is this a good idea? any limitations or potential problems with this?