Okay. I’ll start 
We all know (or should know) that reciprocal links between two sites can be easily spotted by search engines. I’m not saying they’re penalised but they can be spotted and may not carry a huge amount of weight.
Many affiliates now take part in three way exchanges to counter this so my question is:
How easily are three way link exchanges spotted and do they carry any more weight than direct reciprocal exchanges? Should we be looking at, perhaps:
My site A links to your site B and your site C links to my site D instead?