I didn't really believe it was possible, but you truly can give these away at the end to the spectator to keep. They can indeed be signed as well. Truthfully, if they carefully examine the cards, they will probably discover the secret, but there is not obvious slits, cuts, or gimmicks to ditch. You are literally using the card they sign, and only dropping the middle part (that they can also keep).

Now, to the cons of this effect. You have to cut it in front of them, and as you can see in the demo, this can be a slow and tedious process that must be done carefully. If you are good with patter, you might make this less awkward, but it'll still be a slow point in the routine. The payoff will probably make them forget the lead in though.

Second, the prep work for this is complex. You'll need almost a dozen items to create a single card, and you're looking at probably at least ten minutes or more per card in prep. You may eventually get faster with it, but you'll never be able to hammer out one without giving it your full attention for a few minutes.

Finally, the cuts need to be pretty precise in certain areas. I imagine you'll be practicing this initially a few times because that's the toughest part. The move itself to create the link is simple.

If you are relatively comfortable with DYI, this is a fantastic miracle. You'll probably save it for very special occasions only and perform it once per gig, but it's a beauty when done right.