https://www.filepicker.io/ is the best thing that you can integrate with this app which suits your requirement. If you are the owner of the app, you can integrate it very quickly. If not, you can suggest the app owner to do it
Feel free to call me if you need more clarification. I am consulting architect for few companies in US and India on mobile, web and windows/linux/mac apps.
Another service similar to the one mentioned is https://uploadcare.com/. Being restricted to SquareSpace means you need a widget that would be embeddable in their platform, that would come with this functionality.
You should also explore the big video players out there to see if they offer this type of widget (YouTube, Vimeo, Wistia, DailyMotion, etc).
Great question - one that warrants several possible answers.
I work as lead developer at a web studio where we often need to obtain assets (videos, large images, etc) from our clients. Regardless of whether or not Squarespace offers the functionality you're describing (which I don't think it does: http://answers.squarespace.com/questions/1284/must-videos-be-externally-hosted-elsewhere-even-with-a-paid-account), I would typically recommend against allowing direct uploads for potentially massive files directly via your site.
For one, it'll eat up your bandwidth very rapidly. Even if you have a hosting plan that allows for great monthly data transfer limits, or lack thereof, there's really no great reason to take this burden on yourself.
Secondly, you'll eat up your storage. Depending on the size of the videos you're exchanging, the file size could easily run into gigabyte territory very quickly, and at some point down the road you'll likely run into the issue of how to store all those large files.
So what do I recommend? We typically use a third party service like Dropbox or Box, and that has worked very well for us thus far. These services are completely optimized to do one thing and to do it very well: transfer and store files.
The plus sides:
- Optimized for massive transfers
- Very secure
- Each client can set up their own account (or you can do this for them) and simply share folders/files with you - this allows for simple organization and separation per client
Anyhow, loads more reasons out there, but this is a basic summary. Let me know if you have any questions and I'd be happy to help.
All the best,