Strengths: first one to have the idea of cloud storage with synchronization, accessible where you want from any devices, simple design easy to use, exactly same data everywhere you go principle of synchronization, saved in dropbox. com if your laptop is out of use you have access to your files online, enable multi-users to share files, revision-history button to recover deleted files, 2GB storage for free to attract the consumers, pop up if you connect a usb stick or SD card to your computer “do you want to synchronize these files with Dropbox, turn loyal customer into salesperson: 250MB for free if referral (1/4 of Dropbox users come this way), no files capacity transfert limitation.
Weaknesses: need access to internet to download Dropbox, 2GB limited storage for free (competition eg amazon offers 5GB for free as already mentioned by Janine), you cannot store more than the available place on your device, dealing with paid search advertisement, security problem in 2011.
Opportunities: engagement on social media, deal with HTC to be default cloud storage on Androids, talking about it with 6 other phone firms then PC and TV, E marketing benefits: control, reach, interactivity.
Threats: competitors such as Google or Apple could overtake the leader position in B2C market, competition offers lower prices, if Dropbox does not implement himself better in the enterprise market they could loose market shares of B2C market because it has been proven that home market copies enterprise market, possibility of cloud back up system being attacked by external or internal users ? introduction of a spyware through Dropbox