I am writing an application that injects some HTML into the page. I was wondering what the policy is for this. Is it ok or generally frowned upon?
People love this. See all of the grease monkey scripts on meta:
the only people that have anything to say about it are your users.
If your add-on succeeds it is ok, if it doesn't then they are probably frowning. ;-)
For a producer of web content to frown upon an extension would be silly and would not typically be amongst your risks because
- there is nothing they can do about it, legally or otherwise. The content is in the memory of the user's computer.
- it would/could generate negative pr/opinion
- more viscerally, it would be the epitome of petty and would be viewed as such. No one wants to be viewed such a way.
- and ultimately, the goal is to get the content into the user's eyes. Extensions arguably can drive traffic and promote loyalty.