People do judge books by their cover, businesses by their websites, people by their clothes & videos by its quality. Suit up! Remember that in a sales video, 50% of success is the experience that viewer gets. Under the experience section falls the package which may be broken down into 2 main categories:
You video quality, you graphics or any kind of visualizations should be top quality. Make sure you have enough light, if you are shooting your video outside - do it the hour after sunrise or the hour before sunset, make sure the sky & weather overall is clear. If wish to use animation in your video, try using freelancers or stock animation of good quality (ex. videohive.net).
If your audio is bad, no one will watch your video. Bad audio will make even the best footage look unprofessional. Try using professional voice over (ex. voicebunny.com) services if you can not make your own audio sound perfect. For music, choose high quality, as music created the general experience. Imagine this: what if your favorite movie had no music or had poor quality "8-bit tetris" music instead? Thats right, sound horrible. Same here, music creates the mood, music is the business card of your video. Remember though, that you can't use your favorite song from radio due to the copyright restrictions. You can, however, find plenty of royalty-free options online. (ex. www.s7Leven.com