is tagging essential?

Well I don't think it is essential as there is a skip button also on the tag page. But we must tag our discussions as it helps to organise the discussions according to their subjects and contents.Mylot must be using the tags to store them in their database .It is a sort storing similar type of discussions with the help of similar tags.It also helps to search the discussions and it is just because of the tags we get the similar discussions at the bottom of the page so that we can choose the discussions from them to respond. About earnings I cannot say anything as I have never experimented it and I have always tagged my discussions and responses. But even if we don't earn we should try to tag discussions as it just for our benifit.