I am a relatively new ODP editor. Getting elected was fun and joining the group of hundreds (possibly thousands) of volunteer editors was very respectable. My category was filled with about a 150 sites waiting to be reviewed, so I began tackling the task at hand. Going through each request and trying to determine if the site's content is unique, useful and relevant to my category.
Some sites were a perfect match, all I had to do was clean up the title and description and click add. Other sites are just pure junk and are submitted by people seeking ODP links to boost an other page's PageRank, those are easy to detect and delete as well. However, there were many and still are many sites that are border line spam. Sites that look pretty, have nice information but in reality are just affiliate sites. To tell you the truth, I built one or two myself, but I would never dream of listing it in the Open Directory Project (ODP).
There is a thread over at HighRankings that discusses a thread over at the ODP's public forum Resource Zone. It covers a topic just like this, where a "Meta Editor" (those are ODP Kings) can spot these types of sites in a glance. I guess over time and with more edits, I too will be able to spot these types of sites. Until then, the spammers will continue to solicit links from ODPs.