We highly recommend that our plugin users, with dynamic sites, support HTTPS/SSL in order to protect themselves and their visitors from data breaches. In fact, our plugins have offered HTTPS support very early in their development and the option has been free for quite a while. What's nice about our implementation is that it will go back and even secure your past YouTube embeds as they are loaded on their pages. This automatic conversion feature will allow your visitors to avoid having to confirm each non-HTTPS YouTube video you might have embedded in a (newly) HTTPS domain.
Sites that don't currently offer HTTPS support should probably make the jump as it's a fairly quick and easy process. Furthermore, many services exist to help you do this.
If enhanced security is not enough to motivate you, perhaps Google search engine optimization (SEO) will sway you. Recently, Google has just announced that it is incorporating a site's use of HTTPS as a ranking signal in search engine results pages (SERP). In their announcement, they describe this as a particularly small signal at the moment. It is nowhere near the magnitude of other signals like quality page content. However, they explicitly say that they might strengthen the signal's magnitude in the future. Given Google's strong 'HTTPS everywhere' strategy that we are increasingly seeing in many of their services, we can only wonder why anyone would not want to support HTTPS sooner than later. We, in fact, use HTTPS/SSL on our e-commerce pages so that your transactions are secure. Given Google's new signal, we're planning to spread this idea further.