Goodness, what on earth were you thinking of writing about these providers that'd be so libellous?
;-)
More seriously: by the time you'd become a worthwhile legal target, you'd have to be earning a decent living from your reviews that'd more than cover predatory legal costs.
Given the ridiculous number of review sites out site, and how few of them apparently end up in court, I think you can work out the likelihood of such issues for yourself.
You could try being a Yelp for CAs. The exemption for letting other people write their opinions on the internet is pretty ironclad [as long as you honor DMCA notices].
At least to me, it seems the simplest solution is to only sell advertising via a 3rd party bidding system where you aren't involved in the sales process and don't initiate contact. [i.e. Moderation of ads is handled by the 3rd party, not you ]
> Increased risk of losing everything to the American legal system: non-zero
Nah. The worst that will happen is you'll get a letter from a lawyer demanding you take it down. It will be a completely fake letter, with zero basis in law, but if you are worried you can take it down at that point at no monetary cost to you.
Make yourself easily contractible to encourage early contact.
You can also make a way for them to submit a rebuttal that you'll post, that works too.
A lot of states have anti-SLAPP laws that make it much harder for big companies to throw their weight around to legally intimidate legitimate critics, so it might not be as bad as you think:
;-)
More seriously: by the time you'd become a worthwhile legal target, you'd have to be earning a decent living from your reviews that'd more than cover predatory legal costs.
Given the ridiculous number of review sites out site, and how few of them apparently end up in court, I think you can work out the likelihood of such issues for yourself.