Methods and structures are disclosed that allow a user navigation action (e.g., clicking a link in a web browser) to be intercepted for a determination of whether to provide the user an alternate page instead of a requested target page. A user may be redirected to an alternate page based on various criteria, including data related to content of the target page, whether the target page is unavailable, etc. In some embodiments, alternate page determination is performed by a computer system of a website different from a website of the target page. Thus, presenting an alternate page to a user may be based on a target page featuring an out-of-stock product, or one that is currently unavailable with certain features. The alternate page may include more useful content, and may include a current link to purchase the product, a link to purchase a similar product, or other features.