It seems to reason that people who use SnapChat for sexting are doing so to hide the fact that they're sexting, so they might be less likely to admit to it (even on an anonymous survey). Someone who uses text messaging may feel less compelled to hide it at all. This would be especially true for kids (under 18) since you also ask the age on the survey.
Not sure how big a role this might actually play in the results.
Not sure how big a role this might actually play in the results.