Google had announced that they will be considering SSL as a ranking factor. What do you think about it??
I don't think that it is going to effect your SERP unless you are in competition with big sites which already has SSL.
Why should i use it? Suppose, if I have a small blog which has nothing to do with any money transaction then it will only lengthen my loading speed. I don't think that small sites are going to be effected.