An advertisement that loads between two content pages.
One of the most common interstitials is the pop-up ad. Another emerging format is 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.