External Banner / Image Links

Never suspected, but often guilty. This summarizes the impact external banners and graphics have on the download speed of web pages quite well.

First, let's define what we mean with external banners and graphics. Often, when you participate in an affiliate program or a banner exchange program, the banners are not stored on your own server. Instead, you are often given several lines of html code by the banner exchange or the affiliate provider which you then have to insert or embed in your page. This html code often includes a link to a graphic or banner that resides on the affiliate provider's or banner exchange's own servers.

Anytime your page has external links, especially banners, your page's loading speed depends on the availability of the link. If the link's site is down, your page may get stuck too.

For example, when a visitor then enters your page, this embedded code now forces the browser to fetch the banners or graphics on the third party server. Now, if that other server is very busy (and most banner servers are), then any delay caused by the third party server to deliver the image will hold up the download of the rest of your page. In fact, if the banner server is down, it could even cause your pages to stop loading, giving your visitors the impression that your site is slow or down. For each external banner that you have on your page, the delay just multiplies.

The same principle applies to any images or multimedia elements that you may call up from other servers.

To speed up your pages, then, you must either limit the number of banners on your page, or, store a copy of the banner on your own server and modify the links to fetch the banner on your site, rather than from the outside.

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