> I can imagine companies being taxed on adverts, but its a bit cheeky the normal user being taxed (except for large amounts).
Most likely Fileplanet needs the SS number so they can prove to the IRS that THEY (fileplanet) spent money on advertising, so they can lower the tax they owe. Without the Social Security number (there would be a different kind of number if it were another corporation they were dealing with) they can't prove they spent the money (or at least they can't prove they didn't just spend the money by putting it in their officer's bank accounts)
Most likely Fileplanet needs the SS number so they can prove to the IRS that THEY (fileplanet) spent money on advertising, so they can lower the tax they owe. Without the Social Security number (there would be a different kind of number if it were another corporation they were dealing with) they can't prove they spent the money (or at least they can't prove they didn't just spend the money by putting it in their officer's bank accounts)