Twitter ads will make it look like you're a follower of a brand or product even if you are not, according to reports.
The ads are springing up in "Following" lists and may seem as if you're a follower even if you aren't, according to Marketing Land. The ads were discovered by William Shatner -- yes, Star Trek's William Shatner -- who noticed it showed up on his follow list, and found that it had also appeared on other accounts, including Visa's Twitter account.
When contacted, Twitter said that these ads weren't new, but something that has been happening since last year, although Marketing Land appeared dubious that many didn't "notice way before now." Blocking the account does make the ad go away, but it's likely something else will replace it.
The takeaway here is that despite it looking as if you are following an advertiser, you are not. Blocking it won't make all ads go away, but it will replace that specific ad. This may come in handy if it's a potentially embarrassing ad you don't want to look like you are following.