I've been using the RSS feed from eBay to generate affiliate links for some niche categories on the sites I still maintain. I've noticed some idiosychrocies however, and I'm hoping someone can help me out here.

In order to use the feeds, I end up importing them through a reader that then publishes them as dynamic but spiderable content on my site.

The table supports a 255 character URL (varchar), and that works for those feeds... sometimes.

Some of the feeds I "search" in order to get the RSS URL end up being over 255 characters, and as such, don't work. The challenge is, I don't see any rhyme nor reason as to which feeds (searches) generate the longer URLs. It doesn't seem to have to have anything to do with the category I select to search in, assuming I specify one at all, or, to a degree, the number of characters in the the actual search phrase.

Most of the extra characters come in the middle of the URL, as in a bunch of "&dhaq&akjffe&fcnloewi". It doesn't appear, however, if you look at the URL structure, that those characters have anything to do with affiliate tracking either. That piece is pretty easy to spot in the URL.

Moreover, and perhaps most perplexingly, it seems as though the FIRST search I do when I log into eBay always ends up below 255 characters, and subsequent searches sometimes go over.

Does anyone here know enough about RSS feed generation to tell me why this might be happening?