>I purchased SnagIt a few months ago and I have done some screen captures.
>
>Now I am learning how to do video captures. Basically I want to create some small (no more than 10 min) training videos of some features of my app. The first thing that I noticed is that SnagIt creates the video in .MP4 format (Because when I hover over the date-file created in some temp folder the extension is .mp4). If I then, later, send such an .mp4 file to a customer, how easy or difficult will it be for a Windows user to view this? Should I change (if it is possible) the format that SnagIt uses when creating video captures?

If you are happy with Snagit then you do not need to waste more money .MP4 is one of the most popular video formats, just google it and you'll see is very common.

http://www.motionelements.com/blog/articles/what-you-need-to-know-about-the-5-most-common-video-file-formats
http://www.winxdvd.com/resource/mp4.htm

[UPDATE]
You might want to read this:

https://www.dealarious.com/blog/camtasia-studio-alternatives/
https://www.dealarious.com/blog/camtasia-vs-snagit/
[/UPDATE]