Norton have always been a pretty trigger-happy AV though. If it matters so much to you, get your site 'rated', tell your users to get a better AV, or pay for an OV/EV SSL cert (it does not need to be from Symantec, as your OP says, if I understand correctly).
This is where it's somewhat confusing. This is what the Norton Seal generator says:
https://www.websecurity.symantec.com/install-norton-secured-seal
Here's the lowest costing SSL cert from them:
https://www.websecurity.symantec.com/ssl-certificate?inid=prodmenu_sslhome
And here's what Safe Web says:
Which means you're "trusted", even though the most basic SSL cert does not validate anything other than a secure connection.
If you don't get their SSL cert, you're "untrusted" unless it looks like they might crawl your page, community members say it's safe and Norton marks it as such, or you submit a manual appeal which can take 2+ weeks (in some instances 3+ months until you point it out to them on their customer forums).
tell your users to get a better AV
Easier said than done. Your site is blocked prior to them becoming a "user".
So, let's say you're writing for a general audience and you spent hours creating a detailed tutorial on how to cook the perfect steak, you even take awesome photos of the process and include a video tasting at the end. However, someone with Safe Web lands on your site because Google deems it as excellent content and it ranks well for the keywords ("how to cook the perfect steak": 1-10K searches per month on Google) that user typed in. But, they're scared off to read your recipe because it says your site is to be untrusted so they click the back button. Let's just say for the moment that you have Amazon affiliate links on there for a pan that makes that steak even better and hypothetically that 1 user that clicked the back button would've bought it and other stuff while on Amazon too: You lost out on commission.
Your site might not have that general of an audience, so you may not care to target 100% of the segment for your niche. Mine does, however.
To know that 1 person was affected by this makes me mad because I can't just tell them to get better AV; I've lost their visit, possibly forever because they made the mental connection that X site = unsafe far after the fact.
