for a long time I used Delicious to share and store my bookmarks. Some of my friends who are on delicious too, were able to get notified when there was something interesting for them.
There was never any chance to discuss links and make comments to it. I recently changed to google+ to share my links and discuss with friends. That works very good, thanks a lot!
BUT there is one little hurdle. As I said, I stored my bookmarks in Delicious and gave tags to them so it is to search for special topics. In google+ there is no such ability. I would add some tag to a link. I thought about using circles but this will result in more than 1000 new circles (I have over 3k in Delicious!)… I saw those „sparks“ but these seem to be some automatically derived property.
Please add some feature to G+ so it will be easier to tag links!