How Slickstream Impacts Site Speed

Speed Test Performance

If there's one question we get all the time from our customers, it's "How is Slickstream going to affect my site speed?"

Frankly, it's an excellent question. I don't have to tell you how important site speed is to publishers — it has a huge impact on both advertising revenue and visitor satisfaction.

So we decided to dive into the numbers on what actually happens when you add the Slickstream Engagement Suite to your website. I'll get to that below, but first it's important to explain how we work and what the most important metrics to focus on are.

How does Slickstream work?

When you add the Engagement Suite to your site, all of the included search, discovery and engagement tools come directly from the cloud. We don't affect or tie into your servers at all.

We've known from the beginning just how important site speed is, so we designed our software from the ground up to have as little performance impact as possible. For starters, we only load approximately 60kb of javascript on the page. Having a smaller javascript file means faster loading on slower connections and faster parsing when loaded in the browser.

Our script is also loaded asynchronously. That means that while a visitor's browser is loading Slickstream, your content — text, images, and everything else — continues to load on the screen at the same time.


But it looks like Slickstream's Filmstrip loads last... why is that?

Another great question! Our script waits until all of your primary content (you know, the stuff that matters the most) is loaded in the browser before adding our own.

Sometimes, on very slow connections, advertisements can also use up a lot of socket connections. The browser then queues us to load after those ad sockets have done their job.


So how do you actually evaluate speed?

We used Google's Lighthouse tool to conduct an analysis on one our client websites (anonymous here for their privacy) with and without Slickstream. In this analysis we've primarily focused on two key statistics used to evaluate speed:

  1. The amount of time it takes for the page to become fully interactive. ("Time to Interactive")
  2. When the first content is shown on the screen ("First Contentful Paint")

There are plenty of other metrics you can look at (and we'll show them too), but for the most part those two are the most important.


OK, I get it already... Now show me the data!

Here's what this website's performance looked like without Slickstream:


Performance without Slickstream


And here's what it looked like with Slickstream:


Performance with Slickstream


As you can see, "First Contentful Paint" was delayed by 0.2 seconds, while "Time to Interactive" barely changed. In fact, the latter got a little better in this instance, but that's more of a coincidence than anything specific we're doing.

What this shows is that we caused a fractional delay on the first item to be displayed, but no delay whatsoever on when the page was actually ready to use.

The other metrics on display have both positive and negative apparent impacts (Speed Index and First CPU Idle make us look good, while First Meaningful Paint and Max Potential First Input Delay look a little worse), but we'd caution against reading too much into them. There's a lot of variability in individual tests like this, and we focus on those two primary metrics for a reason.


What about on slower connections?

We also tested our performance for users on very slow internet or mobile data connections. Here are the relevant results without Slickstream:


Performance without Slickstream - Slow


And here they are with Slickstream:


Performance with Slickstream - Slow


You'll notice that First Paint was not visibly impacted in this case, but Time to Interactive was a bit longer.


So what does it all mean?

It means we have put an enormous amount of time, energy, and thought into keeping your site as fast as possible, and are continuously improving. While we would never claim to have zero effect on your site speed, it's safe to say our impact is very small.

The easiest way to get a feel for Slickstream is to see us in action on some of our users' sites. Pinch of Yum, DIY & Crafts, and TwoSleevers (read their case study here) are three great examples to start. And don't just take our word for it, you can see our testimonials from happy customers as well!

And finally, when you're ready to try it out for yourself, we offer a completely risk-free 30-day trial of the full Engagement Suite.