You can still link to your shareCG items from your Freebie Descriptions here and request that users go that route, but there's no guarantee that users will go the extra mile just so you can make a pittance off of them viewing your freebies over there. Also, I reccommend that you put the link to your ShareCG portfolio in your signature and when posting about a new freebie upload here, reccommend that users check out your portfolio while they wait for Rendo to approve your freebie! There's no rule against that.... yet.

PS - I've also noticed quite a LOT of people who host their own freebies are posting external links to them here again and the moderators appear not to be noticing this.