Good Question!
The main goal in this question being to attract affiliates, i feel it will be best to employ every means at our disposal; be it promoting TripleClicks or SFI.
Therefore to answer this question appropriately i will say its best to promote both TripleClicks and SFI.
In promoting TripleClicks, we generate sales, have new members in TripleClicks store and even new SFI affiliates.
In promoting SFI, we have new members and ultimately more commissions.