Mailing campaigns are a way to keep longitudinal survey respondents engaged. While mailings usually include a survey answer request, sometimes respondents are contacted between-waves to update contact information or simply to keep respondent contact. Research on the actual impact of these between-wave contacts on response rates is scarce. This paper addresses three research questions: (1) Do between-wave campaigns impact response rate? (2) Does the addition of non-monetary incentives to between-wave campaigns further impact response rates? (3) Do between-wave campaigns also affect other members of the household? Following a one-year break between survey waves, we design a randomized survey experiment assigning respondents to five treatment conditions. Results show that keeping-in-touch mailings did not significantly increase the likelihood of an interview in the National Educational Panel Study for either children or their parents in general. However, when we focus on specific characteristics of the targets, significant differences are found.