Seeking to replicate a popular option from the print world, AdBrite has introduced a new "full page" online ad format, reports ClickZ.

The full-page format works like interstitials that straddle a loading page. But instead of presenting a mere ad, it overlays an interactive micro-site that keeps visitors on the publisher's site rather than sending them to the advertiser site.

The new format does not appear until the visitor has been on the site for a while, clicking several pages deep.

The ads are already on 5,000 sites in the AdBrite network, including Egotastic and Excite. Sanyo, Live Nation and Pennzoil are among advertisers already producing creative in the new format.