I clicked on a few by accident and I'm more than 80% sure that the sites probably contains adware that could hijack your browser (and potentially steal data and private information like birthdays, numbers, e-mails and passwords). Some of these adware hijackers could just redirect your search engine, like from google to bing, google to yahoo, vice versa.
To be safe, if you ever encounter these, don't click on any of the links. Just get rid of them as soon as possible. (Also keep note of the url on the top if it's a search engine hijacker or whatnot)
Adware can come in many forms too, but I'm no expert. I only know the search engine hijack lol.
Just stay safe and don't bring your mouse of finger anywhere near them. Do weekly virus scans or one every few days.