Does Anyone Else have this Problem?

I've had a few people tell me this. I point out the postage and explain that the cards with everyone's names will help me with arranging the table assignments.

I haven't had anyone tell me that, but a few people text or facebook message me that they are going as opposed to sending back our stamped/addressed card or RSVPing on the website. I don't really mind. We are waiting on 108 people to RSVP (our due date is in 20 days) so I'll take RSVPs anyway I can get them lol! I'm sure when I reach out to people we haven't heard from, a few will say this same thing to me.

I had a few people do that, but they were members of the wedding party who already sent us their flight info, so we knew they were coming. One was my sister. I texted her and was like “So since you didn’t rsvp I’m going to rsvp for you as a yes?” She was like “oh yeah, forgot about that one”.
We had maybe 15 people total to follow up with. Took less than 10 min to send out texts, and less than 4 hours to hear back from everyone. So I didn’t mind that much. People have lives and forget things sometimes. Or they genuinely believe you remember them saying they’d come.

I can totally understand how this is annoying, Sara!

You provided a prepaid RSVP envelope for a reason

There will always be those couple of people who don't RSVP and you ultimately have to follow up with. Try not to let it get you down

When is your RSVP deadline? Have you got many outstanding RSVPs?

That's so annoying. I put on FAQ page "Do I send the rsvp back even if I cannot attend?" And I answered "Yes, always send the rsvp card back no matter the circumstance". Don't know how many people will access the website. But if you are concerned about the postage you spent money on I would just reiterate with them that having all the rsvps back in one place is the easiest to keep track. Just make up an excuse. I agree with hannah. Say you need them for the seating chart. Or say so I don't forget to mark you down, please just send the rsvp card back!