Industry Improvements
Webpages which are https (not http), supported by an SSL certificate, are encrypted and prevent snoopers eavesdropping, to pick up sensitive data that people might fill in on the webpage. This concept has been around for a long time, and is the reason why the vast majority of websites that ask you to fill in a form, or make a payment, use https for their sensitive pages.
In the past, web developers didn't make all pages https, because it often would have made the website slower (and a few other techy reasons). In recent years, most of those reasons have become less important, or disappeared. At the same time, people have become much more aware of the potential risks of security breaches.
We try not to admit it too often, but we do have some hardcore techies on board, who actually like keeping uptodate with all this techy stuff (they are clearly not spending enough time having fun with their clubs). They take a bit of pride in leading the way on security things, so in February 2014, WebCollect went https all the way. Several high profile companies have recently chosen to switch to https everywhere.
Https everywhere helps promote trust and prevents a variety of security attacks such as Firesheep. See here for more details. WebCollect also uses HSTS (see here for details) to advertise that browsers should only ever connect to WebCollect via https. As final step, to make you and your members more secure, WebCollect is included on the HSTS preload list. This list is used in Chrome & Firefox to tell the browser in advance that a website uses HSTS and https everywhere, ie the browser will never even connect to the website over the insecure http protocol in the first place.
Does it matter that my website is http?
For the purposes of using WebCollect, it doesn't matter unless you want to embed WebCollect pages within your website. See here for details.
However, even if you aren't embedding WebCollect, you might want to consider going sitewide https at some point, particularly if part of your website is https, and part is http.