| Property | Type | Description |
|---|---|---|
| preMessageImpression | string | An impression web beacon to be displayed when an offer is first displayed on a page in its pre-message state. Beacon should be posted to the page as a hidden image |
| postMessageImpression | string | An impression web beacon to be displayed when an offer is first displayed on a page in its post-message state. Beacon should be posted to the page as a hidden image |