Commitment and Consistency

This is the second law of influence and another one you see every day but just don't realise it.
The idea behind this law is that every one tries to be consistent and keeps to their commitments.

The best example is the one from the book about Christmas presents. Nearly every year there is a must have child's Christmas present and nearly every year they run out of stock before Christmas. So you promise you buy them this X present, but it turns out you can't get in time and thus have to buy them something with the promise you will get them the other X present after Christmas when there is more stock. And there always seems to be loads more stock after Christmas! To keep your commitment to your child you you buy them a SECOND present after Christmas. It is well believed that this type of event is done on purpose by the toy manufacturers. You probably find where the X present is suppose to be, but sold out, are toys sold by the said manufacturer. They basically get to sell two presents to you at this time of year in order for you to appear to keep your commitment and appear consistent to your child.

There are also other laws of influence being used here on your child, social proof as every one wants one and scarcity, they are limited amounts available, thus having one for Christmas will make them special.

Same thing is done with surveys. You sign a survey or petition to say you are against 'Animal Cruelty' then when they later contact you to ask for money in order to prevent cruelty how can you say no without appearing inconsistent, and without backing out of the commitment you made on the survey. There is proof that if you get someone to write down their commitment they are more likely to keep to that commitment!! Powerful stuff!!