If I wanted to give cash, I wouldn't go shopping.
This is why I believe honeymoon registries, etc., are a really, really bad idea.
There are 3 types of wedding-gift givers.1) the people who want to give cash
(bcs, like my ILs, they think this is the most sensible and valuable present--they assume you're saving for a house, or something)
They'll give you cash anyway, so you didn't need to remind them.
But if you make them feel that you are eager (translation: greedy) for cash, they'll feel a little turned off, and they might give you $75 instead of $100.2)the people who sometimes give cash and sometime give presents
(maybe they decide based on how attractive an idea is to them; they like the idea of helping you w/ a honeymoon, or they know money is tight for you, or they looked at your registry and got captivated by your china pattern)
These people, you have an opportunity to influence their choice.
But again, if you make them feel too "coveted" (and asking for money-based things can do that--it did for the OP, actually) will backfire, and instead of giving you $100, they'll go buy something that's $75.
3) the people who aren't going to give cash
You won't change their minds anyway.
But if you make them feel that you aren't interested in the traditional "keepsake" value of wedding gifts (even of useful ones), perhaps by only providing a money-based registry, again, you give them a motivation to be less generous.
And who would -want- to do that?