When a site visitor clicks 'Subscribe', there is no visual feedback of any kind that indicates the button has been clicked. (Well, maybe a slight change in the appearance of the button during the click itself.) For the plugin settings, under 'Form Settings', I have filled in some "text to replace the form with after a successful sign-up" but this does not appear to work. The form is clearly working, however, because each click results in a confirmation email. The problem is that someone could continue to click, unknowingly generating several confirmation emails and being unaware that they have subscribed--a temporary frustration, but it gives an impression of "brokenness" to the website, which we'd like to avoid.
Thank you in advance for your support and for creating this useful plugin! -Frank