Link building method

[halo]

I have made link exchange thread in the link exchange folder here in DP.
But there are many webmaster that request me to exchange link like this method :

I give them my site "A" to exchange and they put link in the "B" site.
After that, they request me to put their site "C".

So, I think this is not reciprocal link exchange.
Someone please tell me what kind of method of this?