Hi Rachel,
A quick an easy way to try and reduce the number of bogus /spam submissions is adding an easy math function to your Eloqua form. The following process walks you through how to create what you need and test out:
In a nutshell if the form is submitted with the correct answer to a simple math function the data will be submit to Eloqua (create a new record or update an existing), otherwise if the field is left blank or the answer is incorrect the form will not post to the second form to update/create a new record in Eloqua.
Check out the link above and let me know if you have any questions.
Jaclyn
