Correcting a bit of an oversight on our part, we recently added an option for affiliates to build XML-formatted coupon feeds. This complements the CSV, tab-delimited, and pipe-delimited (in addition to RSS and javascript feed) options that we’ve had for quite some time. Coupon feeds were actually the last of our downloadable files to become fully XML enabled, joining raw datafeed and Deal of the Day subscriptions, as well as many of our API modules.

Also, this same update added support for incremental downloads of coupon feeds. As with incremental product datafeeds, this functionality allows you to retrieve only new or modified coupons from a certain date (or only coupons that have become invalid since a certain date) if you are using a delimited (CSV, tab-, or pipe-delimited) or XML formatted feed.

To take advantage of the incremental functionality, you simply modify your normal coupon feed download URL by adding one or both of the following parameters:

• incr - Use this parameter to trigger an incremental download. Options include the following:
  • only-modified: This will retrieve all coupons that have been added to or changed in your feed since a given date. This includes newly created coupons.
  • only-removed: This will retrieve all coupons that have been removed from your feed configuration since a given date (say, for example, if a merchant expires the coupon prematurely).
  • all-status: This option modifies the layout of your download slightly by adding an additional “Status” column (or node, for XML formatted feeds). This allows you to simultaneously retrieve new/modified coupons (”Status” = “Modified”) and removed coupons (”Status” = “Removed”) in a single request.
• from - Use this parameter to set the date from which new/modified/removed coupons should be retrieved. Dates should be formatted as “YYYY-mm-dd” or “YYYY-mm-dd HH:ii:ss”. If you leave this off your request (but still use one of the above “incr” options) then our script will automatically determine the date you last downloaded your feed, and use that as the reference point.

Please note: the information necessary to track feed downloads and coupons removed from your feed is only available from July 29th, 2008 forward. Attempts to retrieve incremental downloads for dates prior to July 29th could result in incomplete feeds. It is recommended that you perform at least one full (normal) download of your coupon feed, prior to using any of the incremental options, to “sync up” the list of coupons in your feed.

As ever, all feedback is appreciated.

-David & AvantLink