I absolutely love the idea. I cant remember where I read it or heard it, but physical letters do get much more attention. Nothing against SendWrite, but I think even more attention can be gained via distinctive-looking enveloped letters that need to be cut open and unfolded. A stack of similar-looking postcards will have an impact in terms of volume, but will likely be sorted into a bin and never read. If you have the time and have extra company logo-ed envelopes, please consider sending one by hand as well.