Despite the efforts that were put into data protection and data security, the overall adoption rate of the German contact-tracing app falls behind the estimated threshold of 60 percent which would be needed to suppress the virus effectively. Therefore, we conducted a questionnaire-based study to analyze barriers for the acceptance and to investigate the effect of a video intervention on the acceptance. Acceptance was measured using the technology acceptance model [15]. TAM measures were collected before and after watching the video intervention. Qualitative data on attitudes about the app was gathered through open questions and attitudinal items. 81 datasets from users with no prior experience were included in the further analysis. Results show that the video intervention did not increase behavioral intention (BI) significantly. However, the average scores of two important determinants of BI, Perceived Ease of Use (PEOU) and Perceived Usefulness (PU) increased significantly from 4.00 to 4.61 for PEOU (p<.00) and from 1.93 to 2.16 for PU (p<.001) with high and medium effect sizes. Qualitative data analysis indicates that the main barriers for adoption are perceived high risks and costs but low perceived personal benefits. One third of respondents (27/81) have privacy concerns and more than 40 percent of participants state they see "no benefits"(36/81).