Security - Using A Form In An Expandable Flash Banner?

Later this year I will be producing a few expandable banners for a company. The banner is used to attract people and have them suggest candidates for a competition.I suggested the option of possibly integrating an application form in the expandable banner, which after submission should land the user on the landing page of the site.

But after I suggested this, I started thinking:I can't recall having seen a form in an expandable banner for a long time. Because of this, I assume the use of forms in banners might be considered a big no-no. If this assumption is correct: I am trying to figure out why this is. I understand this will be partially off-topic, since the rationale might be in the realm of marketing, rather than programming.

Programmatically:Are there typical security or other concerns that keep professionals from using forms in banners? I'm thinking maybe csfr attacks, etc. here.Usability:Is using a form in an expandable banner a typical no-no from a usability perspective? I'm thinking maybe banners accidentally closing when filling out the form, or too little space to inform the user of the purpose of the form perhaps?

Maybe it's a combination any of these categories? Or maybe none at all. I'm kind of trying to figure out whether my assumptions are correct, and why. Hopefully someone can shed a light on this matter from the perspective of any of the three categories.