I have been collaborating with Trastik for several years. I have tried various projects and concluded that they are best suited for gray niches. For example, for affiliate programs in casinos, selling dietary supplements, and the like. The thing is, the links don't last long, so it's better not to use them for serious long-term projects. They have guarantees that the link will stay on the page, the site won't be overloaded, and no foreign links will appear. However, in practice, this is not always upheld. Nevertheless, they refund money for lost links; the main thing is to keep an eye on it. And most importantly, they have excellent prices. You are unlikely to find better deals elsewhere.
