Dropbox is not officially supported for sync, however, by following simple rules you can successfully use it.
First of all you have to move you library file to the Dropbox folder. By default it is located at
Now about the rules you should follow to not loose your changes. Snippets loads its data from the file only at launch. When you make changes to the data and save them Snippets will write everything to the database overriding possible changes written to the database in period between the launch and save action. If you have more than one instance of Snippets running on different Macs simultaneously you may lose the data. In result you will have a database version from the client which made latest change.
If you have two or more Macs where you use Snippets you should quit Snippets when switching between the Macs to avoid having more than one running instance at the same time.