Overall chain lifespan is actually pretty good, since the chain doesn't rust for a long while. It does get very dirty, somewhat quickly. If you're willing to use the method on a chain every month or so, it's great for the chain. The gear oil does sort of gum up the other parts, so you should expect to have to clean the chainrings and the RD pulleys each time you lube the chain. Gear oils are designed to be "tacky", so dirt sticks to it like a magnet. I now use chain wax most times (the motorcycle stuff), but the gear oil runs great until it gets too dirty. Mainly a "race" thing that I do, but I used to use it as my only method of lubing chains and I never had an issue except with the short time until a cleaning is needed.