question about robo form and freesamplesite.com

My wife has robo form and uses it in the forms when filling out sweepstakes entries. She heard that if you use robo form on the sweeps site that the site does not actually accept the form, that it as soon as it is received that it automaticly deletes the entry. Does anyone know if this is true or does she actually have to fill out each form..and does robo form leave a footprint that the sites find and delete the entry?

IF this is not the site to ask about this forgive me.

Thanks in advance for any help.