This article is from the eBay FAQ, by William B. Shaw email@example.com with numerous contributions by others.
By adding keywords into your auction title or description that are totally
unrelated to the item you are selling, your auction shows up on a much
greater number of searches. The problem with this is that search results
become unusable since potential bidders have to wade through pages of junk
to find items they want.
First-time offenders are usually given a warning and have their auction
cancelled. Subsequent offenses may result in account suspension.