Interstitial ads (also called transition ads) are advertising that comes between you and the web page to which you're trying to navigate. Or they appear in your transition from one webpage to another webpage within the same website.
The word interstitial means "coming in-between two things".
It's a form of browser hijacking. They annoy people. Don't do it.
MarketingTerms.com "interstitial" definition:For example, you do an internet search, see a promising link, and click on it. But instead of seeing just the web page, you see an ad overlaid on top of the web page, partially or totally obscuring it. It's a commercial intrusion that interrupts your web browsing.
A full-page ad that interrupts sequential content, forcing exposure to the advertisement before visitors can continue on their content path.
Interstitials are a form of interruption marketing. This quality appeals to advertisers who feel Web advertising needs to be more like a broadcast medium to be effective.
Interstitials often draw an above average amount of response and resentment. The high response rates typically translate into higher CPM rates. The high level of resentment may translate into consumer backlash, although the exact long-term effects are unclear.
You want to see what you believe is relevant, interesting, or entertaining web content. But you're rudely confronted with an irrelevant ad instead! The ad may be relevant to the topic, but it's irrelevant because you are seeking information, not products related to a topic.
You're not shopping for anything. You're not in the mood to buy. You feel insulted and offended. You've been tricked into viewing a video commercial with loud, horrible music. Or a digital print ad that's hyping something you don't care about. Even if you might care about such a product, the way it's imposing itself on you turns you off.
Instead of successfully selling the product, you get pissed at both the product and the website that lets these interstitial ads come between you and it.
Irony of ironies! The BusinessDictionary.com definition of interstitial advertising is itself interrupted by an interstitial: an ad for their email newsletter (a very common content type for interstitials).
Interstitials are similar to pre-content video ads, that force you to watch a short commercial prior to enjoying a movie, news report, or other video content. You have to endure the commercial to get to the content.
While the pre-content video ad runs, you're probably resenting it, and making a note to boycott the company behind the commercial. Bad will and negative word of mouth are generated instead of increased sales.
Ads that are unexpected, unwanted, and disruptive to web browsing are counter-productive. They backfire. And they may increase the webpage's loading time.
What's the answer?
Below Content Ads.
These are sales messages that come AFTER the content.
You get the content you want. Now you're happy, in a good mood. When you see an ad below the content, you may be curious. Interested. Prone to investigate a product that's possibly relevant to your interests. Like a book or DVD that expands upon the content you've just consumed for free.
Below content advertising is natural, non-annoying, non-intrusive, endurable. You may skip it and move on, but at least those who do click on the ad or respond to an email newsletter sign-up form, are not antagonized. They will be more qualified, more likely to buy something or receive something free that carries more advertising.
There is also Above Content Ads, which are treading a fine line between Interstitials and Below Content Ads. While they're unexpected and unwanted, at least they don't block your view of desired content. You just have to scroll down a little.
Don't use interstitial advertising no matter how they're hyped to you. Go with below content ads and generate good will as well as increased sales.
Wikipedia article on interstitial webpage.
Smart Computing article on interstitial ads, with Above Content Ad.
"10 Online Ad Formats People Hate Most" from Catalyst Group, as seen on Silicon Alley Insider:
* Banner ads below headers
* Ads that look like content
* Dancing ads
* Auto-expanding half-page ads
* Banners next to logos
* Billboards in the top right corner
* Google text links interrupting content
* Ads with hidden close buttons
* Page Take-overs