You should realize that many of these claims are no more than a cover for fraud. The purpose behind contacting you and others is to get the so-called shipping costs from you, but the prize does not really exist. Would the one who offers the prize really be unable to afford the cost of shipping it?
Sometimes the aim is to get money by means of a phone call to a certain number. The person claims that he is talking to you to work out details about the prize and how to hand it over, and he talks for a long time, so that he can take the cost of the phone call after working out some deal with the phone company.
You have to guard your wealth and beware of the tricks and scams that are all too common nowadays.
If you are certain that this organization really exists and that they are really offering prizes, there is nothing wrong with you taking them and paying the costs of having it sent to you, without taking part in advertising for this company or promoting it when you do not know anything about them or the purposes for which it is working or was set up.
And Allaah knows best.