Depending on the size of the file, it may take some time to send, but during this time, you are still able to have a conversation with your co-worker or friend while the file is being uploaded and made available for him or her to transfer and save to their own computer. When I was working full-time in a marketing department, we did this a few times and it really did save a lot of time, especially since our work email had to go through a company server and was sometimes delayed by ten minutes or more. Additionally, even though this was corporate email, it still wasn’t completely secure. Having a secure IM client can really ease some of these fears.