“Not Secure” will show on sites even if people aren’t filling out a form field.
Google is upping the ante on SSL to nudge more websites toward moving to https://
Take a look at the graphic above. The top image currently shows in the address bar in Chrome for websites that use http:// (i.e., they don’t have an SSL certificate).
The second image currently shows on sites that don’t have SSL whenever someone enters information into a form field on the page.
Starting in July, the latest version of Chrome will show the second notification for sites that don’t have SSL even if someone is not inputting information into a form field.
I’m not sure how many people notice the “not secure” label. But my guess is the next step after this will be to make it more obvious, perhaps in a red color. So it probably makes sense to suck it up and upgrade to SSL now.
It would be nice if Google made this a little easier. Two things it could do are 1) create a one-click WordPress plugin to change to https once a certificate is installed and 2) make it so you don’t have to create a separate instance in Google Webmaster Central when you switch to https.