if you have an affiliate program at CJ, they may be doing uptime or other quality checks. they own some affiliate sites as well, and depending on those linking mechanisms, they may be sending traffic. VC owns some search engines too and retargeting tools, so they may be indexing content for multiple purposes. there are other reasons, but i think you get the point. they might also be scraping your content looking for coupons or something similar. if you suspect something nefarious or if you're just terminally curious, you're going to have to track down more specific details.