Taboola is a native advertising platform from the company of the same name in New York for publishing "recommended" content in a variety of popularly visited news sites and spaces. Taboola is partnered with many publishers (the Atlantic, Tribune, MailOnline, Business Insider, etc.).
I have used Adstream for my publishing/editing company and I loved how it was able to reach different types of clients in different areas of life. To me, that is crucial because I am able to reach a broader audience which in turn helps me package my product differently for different clients.
If you want to have your company advertised on news websites across the United States then Taboola is perfect. If you're looking for clicks and impressions but not so much interested in traffic that is highly engaged and converting often then I'd suggest Taboola as an option to run traffic, too. This is the perfect platform for grey-hat offers and similar ideas. I wouldn't suggest it for running ads on your website due to some strict conditions and the fact that it might not necessarily play nice with traffic coming from Facebook.
I personally am not involved in the decision to renew the product, but I had only positive experiences with the product and thus would recommend its use and renewal.
It was pretty straightforward getting an account set up and having an account rep assigned. Compared to some other platforms Taboola is actually rather intuitive when it comes to navigating the user interface. Pixel implementation was easy and we didn't have any discrepancies tracking conversions. Also the ability to target LALs was very useful and semi-straightforward to upload.
We have a point of contact in Taboola and he has been really great in supporting our campaign. He helped us set up the initial campaign, answered our questions related to the campaign and even agreed when I asked for a lower CPC. Also, while he tried to encourage us to spend more, he never pushed us to the point that it gets annoying.
I love Adstream because it does a great job at streamlining its ads to different components and different industry providers unlike Apple iAds and Google AdMob. It also is very helpful for a new business like myself to reach different audiences and hopefully generate some revenue from these types of diversified ads.
Outbrain doesn't charge a fee for automatic credit card billing. Often Outbrain CPC for the same content is cheaper but not always. The Outbrain UX is not as good as Taboola but recent changes had made them better than they used to be. In Outbrain you can not change images or titles once they are submitted. You also can not clone campaigns which you can do with Taboola
Taboola campaigns have had positive effects on top of funnel activities and engagement metrics though the traffic is not always as qualified as one would like. You will need to carefully tailor your campaign to squeeze out the most relevant traffic.