RSS Ads in Movable Type

I’ve added a short ad for my consulting services to the RSS feed for Simplelinks. The problem with putting persistant content in RSS is that many news aggregators only show an item once unless it changes.

So your persistant item has to change regularly, but not too regularly. If the same item appears in the feed every day, people may get irritated and stop reading your feed. If the item only changes once a month, then the ad won’t have much impact.

I settled on changing the ad weekly. Then I had to figure out how to have content automatically changes once a week. My plan was to have link element use a query string that would be unique each week. Using the year and the week number for the current date would work fine.

MT’s date formatting commands will let me insert the day number (the tag <$MTDate format="%j"$> inserts 087), but not the week number. I considered writing a plugin to add a week number format command to MT (and I still might), but for a quick and dirty way of doing things I turned to the Regex plugin to convert the day number into a week number.

Here’s what ended up in my template, right after the final </MTEntries> tag.

<MTAddRegex name="weeknum">          s|(\d+)|int($1/7 + .9999)|e</MTAddRegex>    <item>        <title>Kalsey Consulting Group :: Web Sites With         Business Sense</title>        <description>Simplelinks is a product of Kalsey Consulting         Group. We build Web sites that solve real business problems.         To find out how we can help your business, ask for a         free quote at <a         href="http://kalsey.com?<MTDate  format="%Y">-        <MTDate format="%j" regex="weeknum">      ">http://www.kalsey.com/</a></description>        <link>http://kalsey.com?<MTDate format="%Y">-        <MTDate format="%j" regex="weeknum"></link>    </item>