Hi Saša,
I think it's definitely better that ads link to your own webpage / blog, because your blog certainly has a more personal approach and explain why you enroll in SFI.
The exception is perhaps the new JMT Gateway: http://www.joinmysfiteam.com/xxxxxxxx, where xxxxxxxx are your SFI ID, because he made a pretty personalized.
And therefore from today I equally advertise my blog, my website and my JMT Gateway,
and that recommend to you and everyone else!