The main benefit is around workflows. First and foremost, if you are in a position where you need external people to sign documents (say you're a photographer and need signed releases), it's a lot easier to send someone a link to the standard document and get them to sign a release then to email them and then call the person and walk them through digitally signing a document. Especially if you're doing this 50+ times a year. And you typically get the documents signed much quicker. It's pretty much the difference between having to mail in a check for every payment vs using a web portal. It's more convenient and there's a faster turnaround time. Oh and you've removed the risk that something isn't signed correctly (was there a section that wasn't initialed?) or that something was redlined. It's certainly not for everyone or every business, but there are certain use cases where the money is well worth it.
It's also a huge win if you need multiple people to sign a document.
Without a tool like HelloSign you need to email the document to each person one by one to get everyone to sign on the same "paper". It's a mess and takes up a lot of time and coordination.
With HelloSign (and other similar tools), you can just send out an email with a link to everyone at once. They can sign the document asynchronously in whichever order they want, and when everyone has done that, you get a notification.
