Appealing - attractive or interesting (http://dictionary.cambridge.org)

Affect - have an effect upon; for example. "Will the new rules affect me?" (http://wordnet.princeton.edu/perl/webwn)

Affective - pertaining to affect (http://mercksource.com)

Engage - to interest someone in something and keep them thinking about it. (http://dictionary.cambridge.org)

Believable - If something is believable, it seems possible, real or true. (http://dictionary.cambridge.org)