First things first, Project Fi is really awesome and allows people from all over the world to experience what we have here in Europe between countries of the European Union. Travel anywhere you want with less concerns on your back, just like if you were at home...
Now, let's talk about what happened to the rule #3?!?!? :D ahah
Answering you questions, I do think it is ok an acceptable to use bidbots to promote your content, it doesn't matter what you are promoting as long as it is original (made by you), that's what Steemit wants. And that's why bidbots were created.
There are already bots like @cheetah, made by the community, that will hunt you down, if your content is not legit or if it is spam. So I think, in terms of abusing the system, you can´t do it to promote trash, but of course you can abuse the price changes and timing of buying the vote, but this is not illegal and requires some skill... so I think it is fine to do it.
As I mentioned earlier, as long as you are not promoting copy pasted articles, almost everything is acceptable.
Advertising on Steemit is being brought to discussion because of the current prices, the developers need a new stream of income. And I think we need to look at platforms like Scorum.com which implemented a new way of advertising within their platform and is working very well.
scorum seems pretty cool ... do you know of other platforms that offer a similar product?
No, I actually don't know anyone else using this type of ads to get some income.
I´ve heard that Steemit.kr (korea) has some type of ads or are trying to implement it very soon. But, I don't speak their language so it's pretty hard for me to understand what is going on there.