The ability to share files without emailing back and forth has been a fantastic tool for small businesses. Sharing any sort of document is so easy these days that we don't realize how much time this saves us. DropBox is probably the most popular free file sharing service, but there are a few other options that you could use along with DropBox.
OneDrive is a Microsoft service that allotts 7GB of space. For Office 365 users, you get 1TB of space! This can be a huge reason for businesses to upgrade to Office 365. Just like DropBox, you can share with any other Office user, and you can create links to give access to non-Office users as well.
Google Drive is very popular in the Android community, but small businesses can also profit from Google's service. Google Drive has a capacity of 15GB for free, which is much more space than DropBox and OneDrive offer. Along with the extra space, Google Drive includes the same features as the other two services, such as mobile access and link sharing.
In conclusion, if you're looking for some more free space for your business, try to take advantage of all the options available. Do some of your own research and expand your understanding of the accessible tools. I have only mentioned a few of numerous file sharing systems. Always be on the lookout for simple solutions.