Erin is a volunteer for the red cross and must go door-to-door seeking donations. Her strategy is to ask whoever answers the door for a donation of $50 right off the bat. If they agree

Foot-in-the-door

Explanation:

The foot-in-the-door technique (or FITD) is a tactic that is used to convince people to comply to a particular action, based on the assumption that if a respondent fulfills a small initial request, they will be more likely to agree to a later, more important request that they would not have agreed to if they were requested to do so outright.