How to sniff out bad links exchanges

what are the methods for finding the bad ones?

[Drum]

With some search engines being picky about the quality of backlinks, I want to make sure I don't trade links with a bad one. How do I sniff out the bad ones, what are the methods?

FFA,
Link Farms,
any others?

[cbpayne]

There are no set rules, but as a guide I check to see if the page of links is in the Google index. If it is, you could assume its OK.

[jdancing]

You may lose a lot of good links because the google index is the dmoz index and we know the story there.

How about take a look at the link page? Then again, link pages are for the search engines not people. Is that good or bad or spam or a link farm? I don't know....

The only sure thing is an in-context link on a content page on a site that is in a related category to your website. But those are impossible to get for most people.

However, when your site becomes popular, in-context links to your site will happen - naturally. Certainly a Catch 22

[rytis]

I ask myself: if search engines did not exist, do I still want to have my site on their link page? Usually when I answer yes the link exchange appears worthy SE wise too. Those who build link exchanges for SEs only, are likely to use tricks to prevent PR leak ("noindex,nofollow" tags, etc) and prevent real visitors from going to links page (naming link to links-page "link partners", putting it on home page only etc).