Yelp has had the ability for businesses to respond publicly or privately to a review for almost a year now I believe.
> "don't artificially alter results, be like Google and let your algorithm work."
The same game happens in the web search world - it's called SEO. Yelp's spam algorithm is decoupled from any advertising, yet since business owners don't write their own reviews, they have less control over their reputation (as opposed to webmasters who change their page content), and are much more likely to come up with conspiracy theories as to why things happen the way they do and consequently often get very frustrated.
It would be a nice to have a Craigslist or Wikipedia-style Yelp (fast, lightweight, and non-evil).
Simply deciding not to show reviews you've written and/or randomly taking them down after they've been up? Sketchy. Showing those reviews to you so you think they're there even though no one else can see them? Ultra-sketchy.
Now, I can understand why they'd be wary of an account that only posted a single negative review, but if you ban someone, you should let them know.
>>"[The] spam algorithm can filter based on how established user is. [Your post was] not deleted & can re-appear on biz page. Still live on your profile."
It sounds fishy to me. Who cares if the review is "still live on your profile" if it's not live on the business page. It doesn't sound like a spam filter to me, it sounds like selective removal of reviews.
Yelp's business model doesn't sit well with me. Even if the allegations of good reviews disappearing for businesses who don't pay up aren't true, the idea that there is a service out there that you don't want but you're almost forced into paying for since it's affecting your business directly feels to me like paying the mafia to 'protect' your business.
If Yelp really does want to help both businesses and consumers, give businesses the ability to respond to reviews for free and don't artificially alter results, be like Google and let your algorithm work. Make money selling ads.
It reminds me of the whole GetSatisfaction drama with 37 Signals from a few months ago (http://news.ycombinator.com/item?id=540540). This type of business model where you provide a business a "service" they didn't ask for then try to charge them for it will never go over well.
[Edit] FWIW this page, found below in relme's comment (http://www.yelp.com/myths) directly answers every one of my concerns with Yelp. If it's true then great, sounds like they're doing things well. I find it hard to write off all the complaints as fictional though.