In a sense there already is advertising, but it is built into the system and not really sustainable in my opinion. I see people use their steam dollars to advertise on the promotions tab, but it only cost like 50 bucks in sbd to have your post in the top 10 usually, and those posts make way more than that. There isn't enough sbd actually being used for these things to make it worth while, also it only really enriches the richer earlier steemians who were here first.

While you may put some money into the system itself to advertise, unless a ton of whales or dolphins upvote your post, only a few hundred people or a thousand will see it is the down side. To spend 50 dollars ona post only a few thousand see is pretty expensive if it does not getthe upvotes, which a lot of them also don't because it is new people with almost no following. Especially if the whole point is to get people to click into your site and buy a product. Steemit is not advertising friendly for getting views, for example on reddit it is quite literally 10 dollars for 50,000 views and you can get between 100 to 1,000 clicks yto your site(much better return)

We need more normal regular poeple here first for the views before the advertisers can come in, but i think we are all on our way. Isee a lot of new accounts lately.