Thursdayboots.com has a really cool way to keep the user on the page. When users need more context instead of taking them away from the page they show the extra content on this page itself. For example, if a user is scrolling down on a page and decides they want to read about their “Highest Quality. Honest Prices.” promise:
Instead of taking the user away from this page (which is risky because online shoppers are easily distracted) Thursday keeps their focus by showing that new content as a slide-out overlay. This is especially useful if the content you need to show is super long. In that case, you could allow the user to scroll on the overlay while the background page remains fixed:
And you can apply this same strategy to the mobile version of the page:
One nice feature of the mobile slide-out overlay is that the little gap on the left margin acts as a visual cue letting users know when X on the top right of the overlay is clicked they will be back where they started. Visual cues matter.