They're actually not disallowed, as iwebsocial said. Google discourages them heavily, because they are VERY likely to create invalid ad impressions and clicks (which is much the same as disallowing them, in practical terms). The traffic itself is not the problem, it's the legitimacy of the visitor's interest that is in question. See their page here: https://support.google.com/adsense/answer/1348729?hl=en-GB There's a very simple "workaround" that solves the problem: build a splash page. AdSense (and other ad programs) do not want traffic exchanges because the traffic is "unnatural" - it's primarily people who are only interested in building up their own sites, not people who have searched for the information available on your site. So you insert a stepping stone in between the exchange and you, which "confirms" they're interested: only those who are genuinely intrigued by what you're offering will continue from the splash page, which - much like any advertising - is the sort of traffic AdSense advertisers want to hit. For example, if your site has all the latest news for hobbyists who love sewing square buttons onto children's hats (I made that up, it's not actually a niche as far as I know...!), you build a single graphic that says something like "Looking for all the latest news about sewing square buttons on children's hats? Visit the only authority site on the Internet NOW!" and add a "Click here" button. Host that page yourself (my.domain.com/splash.htm or something) and put it on the exchange as your site. Don't host the splash page on the exchange - you want it to have a sensible, non-exchange URL, on the same domain or another one you own. Anyone who clicks on your splash page can be (fairly safely) assumed to be interested. The site (and AdSense) see the traffic coming from a splash page, not a traffic exchange, which "legitimises" it. It's like they clicked on your ad somewhere online and arrived at your site because they want to, not because an exchange sent them. Problem solved. Hope it's useful.
Yes, I think the point of view of TIEro fits better the recommendations guideline of AdSense. So... for ban every doubts, go for naturally white SEO'ed traffic
traffic exchange services are not good for adsense enabled blogs. This is also not for good hosting servers also.
I would have to say no to this question. Traffic exchange companies suck really bad. You should try a company called Target Finder Marketing. It $0.20 per click and the traffic is keyword targeted.