For energy conservation purposes it is not sufficient to rely on energy efficient technology, energy savings also require changes of behavior and daily routines. However, ICT can play an important role in supporting behavior change. A first step to behavior change is to actively deal with one’s energy consumption. We present an interactive online application called aWattgarde which provides customers of an Austrian utility company with insights about their electricity consumption and with suggestions on how to reduce it. Customers are incentivized for reading their electricity meters and entering the readings online on a weekly basis. In this paper, we use aWattgarde as a tool to evaluate the effects of various motivational elements on usage. The evaluation bases on usage data of almost 7’000 customers who have been using the website for six months. In our evaluation we focused on different incentive systems as well as commitment- and infotainment strategies. We found that online applications that aim at motivating energy conservation should incorporate bonus points to reward desirable action immediately, commitment features to get people into a routine and using the application regularly and in the end should provide information in a playful and interactive way.