Nina+Matt,
The law requires that a non-immigrant visa applicant demonstrate that they will not become a public charge while they are in the USA. If a non-immigrant visa applicant cannot afford their trip to and stay in the USA using thier own financial resources they need a sponsor. Simple as that.
In the case of the K visas, most applicants do need a sponsor and their petitioner is the most logical first choice to sponsor them. But, if the petitioner cannot afford to sponsor them, then someone else who does have the necessary financial resources can be the sponsor.
Whoever the proposed sponsor is, it's also a requirement that the consular officer be comfortable that the proposed sponsor will 'put their money where their mouth is'. Some consular officers are not comfortable if the proposed sponsor does not have close ties to the alien who they propose to sponsor.
Yodrak
QUOTE(Nina+Matt @ Jun 18 2007, 11:48 AM)

hey everybody!
my fiance read something about visas being denied cause the petitioner was unemployed even though they had a co-sponsor!
do you think thats right? why would you need a co-sponsor then?!
can someone help me out with that please?! any opinions and experiences are appreciated!