Emailing large files was often difficult, and carrying a USB stick was not ideal either. In my original article I described Dropbox as a place where files synchronize between devices. A change in one place then appears elsewhere. You can also share a file without sending a heavy attachment.
Sync or share a copy
These are different choices. A shared folder can suit people working together on files. A view-only link is more useful for a finished document or a set of holiday photos. According to Dropbox's current guide to shared links, recipients can use such a link without becoming members of a shared folder.
Check who can open the link and whether anyone can edit. A file you share may be passed on. If a document keeps changing, agree which version is authoritative. Otherwise, you may still end up with several copies carrying the same name.
The enduring question
My old article mentioned free storage and rewards for inviting users. Offers change; they tell you little about whether the workflow fits. First ask whether you need synchronization, collaboration or delivery only. Then choose a service and access settings that match.