And no rule per se, but unless you have a habit of walking into your living room or your friends houses and announcing things just like you did above, the community as a whole finds it at least weird if not distasteful.
I know my friends would tire quickly of me just popping in to sell them on something.
I think it just may be the way this was written as a commercial instead of the personalized feel of the other things you’ve posted. And just so happen to put your links at the end.
May very well just be the tone here.