Drop Us a Line: Table Numbers & a Note

Our postcard "guestbook" is officially in the works! I've ordered the first batch of postcards, yes I said first batch. We originally were just going to do a few designs, but later decided we want to put the postcards at each table. As I've mentioned before, I'm in love with the postcard guestbook and hope every single guest at our wedding fills (at least) one out (There are different questions on different designs).

I recently went to a wedding and I think less than half the guests signed the guestbook. I'm thinking if we put the postcard at each person's place setting they might be more likely to fill it out, if only to get it out of the way for the food.

So to encourage guests, we'll have a postcard at each place setting, with pens and a sign explaining what to do. The sign will actually do double duty as it is also working as our table number. The front side will have the table number.
The back has a little note asking guests to "Drop us a line". I think these little signs are my favorite wedding detail so far.
The Note says: Drop us a Line....
Please fill out a postcard with your wishes, advice, memories or thoughts for the bride and groom. The Mother of the Bride will be sending the postcards to the newlyweds throughout the first year of their marriage to help them remember this special day. Please drop the card off in the box at the enrtrance.

I bought the Martha Stewart anchor punch about a year or two ago with no idea of what to do with it. Then as I was thinking about the "drop a line", it just seemed too perfect! Plus we already had Baker's Twine, and left over navy and white paper from Paper-Source. These little add on notes were made from all the left over materials from past projects.

Do you think people will actually fill these out or am I wasting too much time on the guestbook?