I'm not an accountant, but as companies are not required to send you a 1099 until the end of January (with the same info reported to the IRS) I'm not so sure this is going to work. Companies do the calculations in January, so once Dynata receives the W-9 after January 1 they would do the math and send the 1099. The tax liability doesn't just disappear simply because it's a new year. And as you pointed out, if you don't submit the W-9 form at all they can stop giving you rewards or just freeze/close your account.