"Pre" Save the dates?? Please Help!

[XxStaceFacexX]

I'm looking to get an idea of how many guests actually want to attend my DFTW. I'm inviting somewhere between 150-200 guests. I know that half (or possibly more than that) will choose to not attend, however I want to know how many guests would attend, so that I can choose the venue for the reception. Has anyone done something like this? I'm planning on printing up a little letter and making an announcement at my engagement party next month and having them place thier response in a basket. What can I say so that people don't feel pressured or obligated to make a decision so quickly?

 

[JaxTeach]

I didn't do a Pre-STD, but we did send out pre-RSVP's. Of course we started planning our December '07 wedding in May '07. I designed a card listing the basic information for our wedding. Inside the card was a "pre-RSVP" postcard for our guests to return. That gave everyone a heads up if they need to ask off from work and gave us an idea of who was even interested in attending.

Here are some awful pictures: