>Google Accounts are free and simple to create, so if a user doesn't want to "link everything together" they can create a new separate account that they only use for Kapwing. Plus, we're aren't "linking" to your Facebook/Google data; we're just reading your name and email from your account.
I don't know about Kapwing, but the problems with this:
1. Simple to create? I just went to the page and it wants birthday, gender, phone number, among other things. And then on top of that, I'm sure there will be a bit more work to confirm my identity (text message or email). Certainly not trivial. And will I need to go yet one more step to confirm anything from Kapwing?
2. Do I need to now monitor this new account for stuff from you? Overhead for me to maintain yet another account, in order to maintain yet a third account (Kapwing).
Benefits of email for me:
1. It's easier to create a throwaway temporary email account than to create a Google account. It is intentionally easier. They exist just for this purpose. Not sure if you've tried it.
2. Clicking on a confirmation link is easy for me.
>Having user's "real" identity helps with validating credit card transactions, sending follow-up receipts and confirmations, and personalizing the site.
This is where creating a separate Google account just for your site would be a negative. I'd have to set it up to forward to my email. I'd rather just get the email from you directly.