I can only assume that since you are wondering if this is a "scam", that you are incapable of reading. Try reading it real slow, once more. It explains everything you want to know. OldTrader
Considering the SSFs move with their underlying, it is more return for the same risk over a long time frame because you reduce margin interest or if you are short, short interest. Theoretically the positions are about the same otherwise. Anyways, it's all explained in the email and OldTrader was only trying to offer a suggestion. People on here are so defensive and emotional. I hope none of you guys trade like that.
It's not a scam; in fact, it will reduce IB's float-income if implemented by clients. An EFP or conversion arb will beat IB's interest payments by 5 to 40 basis, based upon prevailing spreads. IB gains nothing from a client trading a rate arb.
The angle, very simple -- http://www.interactivebrokers.com/en/general/about/mediaRelations/03-16-06.php?ib_entity=jp