Pros:
- It is compact and portable
- Save one from the extra stress of doing 2 factor authentication
- Secures one from phiser attack as it is hardware and detachable
- It has a fabulous support and works for almost all platforms.
- The mobile version for iPhone gives it more user friendliness.
- It is very easy to setup making it easy to use by anybody
- It is an open source project with good developer support making it an easily integrated solution.
Pros:
- It is very small and can be easily misplaced
- It is expensive for an average user from a developing country and would push them to stick with the free service of the regular ones