Ad Peeps uses a variety of settings to decide which ads
qualify to be shown. Some of these include Ad Size, Target
Zone, Impression or Click limits, etc.
In the event Ad Peeps can't find any eligible ads to show, it
will use the least restrictive settings and look for any ads that
are (1) the same size of spot its trying to show AND (2) the
ad is marked as default.
If available, Ad Peeps will show that ad to your visitor
instead. The Default Ad concept simply allows you to
show "something" there instead of a blank spot. Default ads
are not counted against impressions.
Some good uses of a Default ad would be to designate
an "Advertiser Here" banner as a default ad.
To Designate An Ad As "Default Ad"
Edit the Ad Settings of Ad > Other Tab > Click ON next to
Default Ad
Save.