You\u2019ve seen them before: irrelevant Facebook ads that pop up in your feed, leaving you scratching your head. Ever wonder where they come from?\u00a0\n\n\nFacebook determines which ads it serves you based on a number of factors, including the information you share with the social network, Pages you like or engage with, ads you click on, apps you use, websites you visit and information from its data providers and advertisers, it says.\u00a0\n\n\n\n\n\n \nAlso on CIO.com:\n\nHow three old-school companies became digital platform players\nLife in the fast lane: What gigabit Internet makes better\nThe 15 best free SEO tools\n\n\n\n\n\nThat means if you\u2019re thinking about buying a new car and start to research your options online, Facebook might show you ads for new or used cars, or deals for remote car starters or car washes, based on that activity.\u00a0\n\n\nOf course, Facebook doesn\u2019t always get it right. Hidden in your advertisement settings is an option to review and edit the interest list that informs which ads you see, as well as a tool that explains why you were served a specific ad.\u00a0\n\n\n\u201cWhen we ask people about our ads, one of the top things they tell us is that they want to see ads that are more relevant to their interests,\u201d the company said in a blog post announcing the features in June 2014.\u00a0\n\n\n[Related: How to prioritize your Facebook news feed content]\u00a0\n\n\nReviewing and editing your ad preferences \u2014 particularly during the holiday season \u2014 could be a worthwhile exercise, especially if holiday shopping has monopolized your online searches and skewed the ads Facebook shows you. Here\u2019s what you need to know about editing your ad preferences and opting out of interest-based advertising.\u00a0\n\nHow to edit your advertising interests\u00a0\n\nTo review the list of interests Facebook compiled about you based on your online activity on Facebook and other websites and apps, visit the Your Ad Preferences page. You can also find this page by visiting Settings > Ads, then click Edit next to \u201cAds based on my preferences\u201d and select \u201cVisit ad preferences.\u201d\n\n\n\nYour Ad Preferences page displays more than 10 categories, from food and drink to sports and outdoors. Click any of these categories to view the interests \u2013 some categories may have well more than 100 listed.\u00a0\n\n\nYou might notice a mix of random and on-point interests. Under my \u201cHobbies and Activities\u201d category, for example, the interests \u201cmoose,\u201d \u201cdental floss\u201d and \u201cWinter dolphin\u201d were inexplicably listed.\u00a0\n\n\nFor an explanation about why it was included, hover over it. Apparently I had clicked ads or liked Pages related to those interests. (A Google search for \u201cWinter dolphin\u201d turned up links about a dolphin named Winter who had a prosthetic tail, which I vaguely remember watching a video about.) Other categories were far more accurate: The \u201cSports and Outdoors\u201d category correctly listed the New England Patriots, Boston Red Sox and Syracuse basketball as my interests.\u00a0\n\n\nTo edit your list, hover over an interest and click the X to delete it from the list. You can\u2019t remove interests in bulk, so this might take some time depending on how detailed your list is. Alternatively, you can add preferences to your list by typing it into the field at the top.\u00a0\n\nHow to adjust your ad preferences\u00a0\n\nAnother way to address misguided ads is to correct them when they appear in your news feed. Hover over an ad and click the drop-down menu, where Facebook lists four options.\n\n\n\nIf the ad is irrelevant, choose \u201cI don\u2019t want to see this,\u201d which removes the ad from your news feed. If the advertiser is irrelevant, choose the second option, \u201cHide all ads from [advertiser].\u201d Click the third option, \u201cWhy am I seeing this?\u201d for an explanation of why Facebook served you that particular ad.\u00a0\n\n\nMuch like Your Ad Preferences page, these reasons vary: It\u2019s possible you liked a related page, clicked a related ad or your other online activity indicated it was relevant.\u00a0\n\nHow to opt out of interest-based ads\u00a0\n\nInterest-based advertising uses your activity on websites and apps to help the social network learn which ads might interest you. If you don\u2019t want Facebook to use this information for the purpose of showing you ads, you can opt out in Your Ad Preferences page.\n\n\n\nClick Edit next to the first option, \u201cAds based on my use of websites and apps.\u201d This option does not remove all ads from Facebook; instead, the ads you see may be less relevant.\u00a0\n\nFacebook is not alone in using interest-based advertising; it\u2019s a common practice among other websites, including Google and LinkedIn. Turning off this feature on Facebook prevents the social network from using your online habits to serve you ads, but does not impact the other participating companies. To turn this off for all websites, visit the Digital Advertising Alliance.\u00a0\n\nThe Digital Advertising Alliance page will scan your browser and show you the participating companies; which companies have currently enabled customized ads for your browser; check whether you have already opted out from participating companies; and choose any or all companies to remove. Like opting out of Facebook\u2019s interest-based ads, this won\u2019t eliminate advertising.\u00a0\n\nNote that this tool removes interest-based ads on your current browser. If you use multiple browsers or other devices, you\u2019ll need to perform the same steps to remove interest-based ads from elsewhere, as well.