celgins - 8:16 pm on Oct 17, 2012 (gmt 0)
I am beginning to wonder if that could actually be the case. What's stopping competitors adding links to a directory / website then disavowing them.
I'm guessing nothing is stopping them from adding the links to a directory site. But this is the type of situation where I believe Google could apply a "freshness" test.
If a competitor adds their site links to your directory, and then submits a disavow.txt file to Google the next day, it should raise a red flag. If Google is crawling your directory site, they will know when the link appears, and they will certainly know when they receive the disavow.txt file from the competitor.
Could a competitor add his/her site links to your directory and wait 6 months to submit a disavow.txt file to Google? Probably. And there are so many other possibilities for gaming this system.
I just wonder if the Google engineers thought of all of these angles and potential hiccups from rogue competitors.