{"id":9867,"date":"2023-09-19T12:00:40","date_gmt":"2023-09-19T10:00:40","guid":{"rendered":"https:\/\/chapmanbright.com\/?post_type=resources&p=9867"},"modified":"2025-11-17T12:57:35","modified_gmt":"2025-11-17T11:57:35","slug":"why-email-duplicates-matter","status":"publish","type":"resources","link":"https:\/\/chapmanbright.com\/nl\/resources\/other\/why-email-duplicates-matter\/","title":"Why Email Duplicates Matter","content":{"rendered":"","protected":false},"parent":0,"template":"","cb_resources_category":[91],"class_list":["post-9867","resources","type-resources","status-publish","hentry","cb_resources_category-other"],"acf":{"banner":10616,"title":"Why Email Duplicates Matter","text_overview":"Why exactly should you be concerned about email duplicates? Well, there\u2019s a number of reasons, and this blog post dives into five of them, as well as a few questions to help you start tackling your duplicates problem. ","image":10624,"button":"Read more","components":[{"acf_fc_layout":"layout_textblock_full","background":"grey-light","title":"","text":"This article reflects Chapman Bright\u2019s earlier focus on Marketo and 'classical' marketing automation.\r\nToday we help B2B companies scale productivity with automation, AI, and agents. Read more<\/a><\/em>","button":null},{"acf_fc_layout":"layout_textblock_full","background":"none","title":"","text":"This blog post originally appeared on the Marketo blog, written by Katja Keesom, an active member of the Marketo community as well as a Chapman Bright Senior Consultant.\u00a0<\/em><\/strong>\r\n\r\nThe health of your database is of great importance to the effectiveness of your Marketing Automation. So why exactly should you be concerned about email duplicates? Well, there\u2019s a number of reasons.\r\n\r\n \r\n
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  1. Personalization<\/strong><\/li>\r\n<\/ol>\r\nLet\u2019s say John and Chris both work for Example Inc. and in both their profiles the email address listed is info@example.com. For your next campaign, John qualifies and is sent an email. With the same email address for both men, you have no control over who reads the email, so you might not be addressing the person reading the email.\r\n
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    1. Activity history<\/strong><\/li>\r\n<\/ol>\r\nFollowing from that scenario, if Chris opens that email instead of John and clicks on a link, Marketo does not attribute those activities to Chris, but to John instead as his mkto-token is associated with the email. Better yet, if Chris had accepted a cookie, that cookie is now also associated with John. That means subsequent web visits by Chris will be attributed to John. You can imagine how this will become quite a mess over time as multiple interactions take place and cookies swap back and forth.\r\n
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      1. Lead processes<\/strong><\/li>\r\n<\/ol>\r\nAgain, following through this scenario, John will be accumulating points in your lead scoring model, whilst the real activity is by Chris. It is entirely imanginable that this will hit the lead scoring threshold and John will be sent to Sales for follow up. That will be quite the surreal conversation, as John knows nothing about all these interactions. So duplicates will mean your lead scoring process becomes ineffective.\r\n
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        1. List uploads<\/strong><\/li>\r\n<\/ol>\r\nIf you have included an email address in a csv file to upload into Marketo and this email address exists in Marketo more than once, the most recently updated record will be selected for the list upload. Of course there is no telling whether that is the record you actually intended, risking incorrect data being reflected in your campaign for that person.\r\n
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          1. Duplicates are magnets for extra duplicates<\/strong><\/li>\r\n<\/ol>\r\nIf you allow email duplicates in your database, it opens the door for other duplicate sources. Over time, this will create quite a mess in your database. An example: Your CRM sending a person to Marketo by its CRM unique Id will not be matched to a previously existing Marketo record with the same email address that does not have that CRM id.\r\n\r\n \r\n\r\nSo duplicates cause headaches, I get it. But what do I do about them? Unfortunately, there is no magic bullet here. Depending on your specific use case you need to simply make sure to manage them and keep the impact to a minimum. Some considerations:\r\n