The Canadian 24-Hour Movement Guidelines for Children and Youth (Guidelines) recommend that children and youth Sweat, Step, Sleep, and Sit the right amounts. This integrated movement approach shifts from traditional guidelines' that focus on isolated behaviours. An innovative online activity hub - Build Your Best Day (BYDB) was developed in 2016 in partnership with Guideline stakeholders to disseminate the Guidelines among parents. Using the Hierarchy of Effects Model (HOEM) and cost-effectiveness analysis (CEA), the objective of this study was to determine if BYBD was an effective and cost-effective means of Guideline dissemination. Effectiveness was measured by HOEM measures, parental support and hub utilization. An online survey was administered to three different cohorts of parents (n=1208, 939, 751) at three time points (3-, 12-, and 17-months post BYDB release). ANOVA's were used to analyze survey responses. To assess the hub's utilization, data from Google analytics were collected and analyzed. Costs consist of personnel, and hub development. The results revealed negligible changes in social cognitions (e.g. attitudes, intentions) over time (p>.05). Parental support for moderate-to-vigorous physical activity increased over the three timepoints (p<.001). There was minimal change in BYBD engagement, varying from 746 to 21,424 users per month, despite promotional activities. A total of 93,068 users visited BYBD over a 12-month period, however only 10% completed the full planning activity. We estimated a cost of $183.50 per user to complete the hub experience. These results suggest that BYDB was neither an effective nor cost effective method for disseminating the Guidelines among parents.