Affidavit of Support for DV Lottery Winners.
Affidavit of support is known as sponsor document in many part of the world and now it is must for all the DV Lottery winners who want to have their visa under this program each year. Its (Green card lottery) instruction clearly states that all the winners must provided one affidavit of support through the I-134 form on the day of the interview. The petitioner must be an American citizen or must be an American LPR holder. It can be a relative or friend of yours. Others can't provide this Affidavit of support to the winner.
Also the petitioner must provide required relevant official papers along with his financial report papers to the winner before the interview.
On the day of their interview applicants must provide these documents to the interviewing consular officer. This requirement will apply to those winners in the America too when they want to change their current US status to the U.S LPR status, through USCIS office.
Affidavit of support must be provided through the I-134 form. While some consular offices want them in I-864 form from the green card lottery winners to issue the Immigrant visas. Some time the agreed petitioner may change his mind and don't want to support you, so there is no problem in changing with a new petitioner's name and information on the day of the green card lottery interview.
Those people, who don't have a petitioner to provide an affidavit of support for them, can proof that they have on arrival job arrangements and enough funds to meet their needs in the USA. In this case, the consular officer will decide on whether to issue the required immigrant visa for the green card lottery winner or reject the visa depending on the funds and the available job.
American Government had introduced this rule as it had found out that many winners who had arrived in the USA in the early years without proper support in the USA, did suffered without proper Jobs, lodging and food. Because of this they had introduced the Affidavit of Support requirement for the current DV Lottery winners to be issued with the required visas.
Some of the petitioners may not like to give you the affidavit of support and their financial report to you. In this case they send the scanned copy to the relevant consular office through email just before the interview date.