The way Twitter handles threaded conversations means that any reply you post to a promoted tweet can be seen by anyone else, if you want to have a little bit of fun with particularly irritating and poorly targeted (and persistent) ones.
I have used Twitter for six years and benefited hugely from it yet I've never paid them a bean. It would be churlish to begrudge them revenue and I wish them well in collecting it.
One of the ways I think they're doing this is to charge people to promote tweets - they've been doing it since at least July 2011. Note that I said people and not advertisers or companies. Anyone can pay to promote their tweet to a bunch of people. And they do, and some of them are ... well, a bit pointless.
Initially it was mostly companies promoting a product or service through Twitter but now it seems that anyone with less sense than money can join in.
Here are some that I've had promoted into my timeline.
None of them appear to be advertising anything (the last one has a link but it's just to a picture of a bit of plastic-coated wire). I suppose this is a modern-day calling card of sorts.
Genuine company-promoted tweets are a bit different. Some are useful, interesting and relevant others are poorly targeted and there seems to be no way of avoiding them. Blocking the sender makes no difference as far as I can see, and replying to them rarely makes much of a difference, but doing so did give me an idea for some mild sneakery.
You can comment on promoted tweets
Thanks to the way Twitter threads conversations a tweet becomes part of a conversation once anyone replies to it. When you click on the tweet you can see most(1) of the other tweets that people have sent in reply. This means that, merely by replying, you can 'graffiti' a promoted tweet. Unless Twitter makes it so that promoted tweets can't have replies there's not much the company can do to stop this commentary - unless they delete that tweet.
To be honest I think this sort of thing should probably be reserved for only the really irritating tweets that are irrelevant and persistent - let's not all be mean to people who mis-send a tweet every now and again.
Do promoters understand this?
Having clicked on a few promoted tweets now (both from companies and people who seem to have promoted a tweet by accident), and seen the replies, it seems that sending out a promoted tweet can really open you up to some unpleasant responses. I don't know if Twitter is warning advertisers - I assume they're being told that their tweets are being targeted to relevant people but having received so many that are so off-target this system might need to iron out a few glitches. Mis-targeted tweets probably increases the unpleasantness of responses as people find these promoted tweets pretty irritating. The problem, for advertisers, is not just the unpleasant replies ('snark yes, unpleasantness no' would be my motto) but the fact that others can see the unpleasant replies thanks to threading.
Skeptical activism - an opportunity
This could backfire horribly. I got the idea from a disgruntled air passenger who paid for a tweet to be promoted to people telling them that the airline he travelled on had terrible customer service. About a year ago the Advertising Standards Authority adjudicated against an advert for a company that makes a tape that you stick to your skin to prevent muscular problems and injury. It's utter nonsense (aka kinesio tape) but the products sell well despite this. I jokingly suggested that a bunch of people crowdsource funds to pay for a promoted tweet that sends the link of the ASA's adjudication on kinesio tape nonsense to people on Twitter who mention the tape. Though I'd certainly not want the tweet to come from my account ;-)