Forty percent of American adults click links, photos, and gifs of kittens on Facebook on a weekly basis. What aren’t they clicking, at least according to the users surveyed in a poll by the Associated Press and CNBC? Ads. That may be because most Americans who use Facebook don’t seem to much trust the social-networking site, with only 13 percent of users surveyed in a recent poll saying that they trust the site “completely” or “a lot.” That lack of trust in the site may hamper ad sales, even as the company prepares for what promises to be one of the biggest IPOs in history. In the AP-CNBC poll, a full 83 percent of those surveyed said they “hardly ever” or “never” click on Facebook ads. On Tuesday, General Motors pulled $10 million worth of ads from Facebook after the company felt that ads on the site may not be paying off.