When you look on the internet, you see that websites differ greatly in this regard. How will you address people on your website from now on? This choice also has consequences for your newsletter, advertisements, and Social Media use. When it comes to new contacts, is it disrespectful when you address them informally? When it comes to existing relationships, does a distance arise when you (suddenly) address them formally?
 

Adapt to the target audience!

I was raised "polite" with the use of 'u' and I do that almost always with people who are significantly older than me. Also, when I speak to a client for the first time, I use 'u'. My doctor, my dentist, the lawyer, the gentleman at the bank and the notary, are 'u' to me.
 

Professional or chilly, cold detachment?

'U' is more business-like and professional, but it also creates a distance; do you want this? Is the use of 'u' still of this time? When this leans towards "chilly, cold detachment", does that suit you? (This certainly does not suit me).
As I get older, I notice I switch to 'JE' more often. That feels less distant and creates a bond faster. If people address me with 'u', I often quickly say they can say 'JE'. I also always say I am "Sonja van Breen" and do not call myself "Mrs. van Breen".
 

Personal!

When I am addressed with 'je' on a website, it feels more personal and direct; I recognize myself in this. 'Je' and 'Jij' are the 2 most powerful words on a website; I get the feeling that it is about me, not about someone else. I feel addressed, which is exactly the intention!
 

Be consistent!

On the internet, the "tone of voice" is generally more informal than on paper. It doesn't really matter that much to the reader, as long as you are consistent.
 

Watch out!

When you use 'U' and 'JIJ' interchangeably because you are not sure, it can come across very strangely: "as if someone you are talking to suddenly starts dancing or making a bow in the middle of the conversation".