When you create profiles for your brand or organization on various social media accounts and networks, you should be thinking about more than just your profile name being used. Selecting the appropriate image or photo to use as your avatar is just as integral as the right profile name and website link you are displaying. All of these things have a great impact on how your profile, company or brand is being perceived. A successful avatar will help people relate and connect with you.
Using the same avatar or similar one on all your social network accounts can help to establish your brand and make it easier for other users to recognize you and feel like they are familiar with you and your accounts. 
Using an image of yourself as an avatar can bring you more credibility and trust. People want to get the feeling that there is a real person behind every email, profile, website or whatever other thing that represents yourself and the services you provide.
What to use?
If you are a company, use the logo. Having trouble fitting your logo into those universal square dimensions? Try to use a portion of your logo or an icon that is in the same styling. Another option is your symbol. This could be a picture of something that represents you even further than the logo, for example we use Charlie for our Twitter profile pic.
If you are creating a personal account, the best option would be a simple photograph of your head shot. Try to use an updated picture — you don’t want to deceive people. Imagine that face-to-face meet up and someone says how different you look. I get that sometimes — my beard comes and goes 
Changing your avatar too often can be confusing to people trying to find you by your photo or the avatar they are used to seeing associated with you. If you must change it out, make sure you have a good reason for doing so. I know that personally when I scroll through my TweetDeck during the day, I look for specific people by their avatars first. If they change them often, it is harder for me to spot them. However, if they are interesting enough, I will find them, regardless if they have a new avatar.
I agree that an avatar should become an integral part of your brand. However, I also know that people buy from people they know and trust. Most people would like to see a picture of you rather than a comic avatar or a company logo. So unless you aspire to become a big "brand" or household name one day, I suggest using a current picture. It should also be appropriate to your company, field or position. I want to present a geeky and relaxed impression and chose a picture while on vacation and on a glacier in Alaska . But if I were a lawyer or an accountant, I would select a more professional picture, i.e. suit and tie.
I believe that avatars are important and integral part of social media profiles. As mentioned in the blog it helps to have an identity and establish brand in various social media profiles. I think it is most fundamental point that every person who uses social media should know to have correct and apt avatar to build trust among strategic partners.
Anyway thanks for posting useful information.
Its a good thing (in my opinion) to be able to put a face to the name. Just makes things more personal.
Awatars make communication in social networks much more vivid and thrilling, I can't imagine my social network mates without their awatars.
Yes avatars should also the same across all sites you use, but do you think? Is an avatar with personal face better than an avatar with your logo?
Its a good thing (in my opinion) to be able to put a face to the name.
How about a recognizeable 3D avatar of you, with different animations that you can apply to show your mood?
You can do it at http://www.evolver.com. create your avatar then go to this transport link: http://www.evolver.com/products/imagescene.aspx
A good avatar will help you to promote your product, but a bad one can spoil all your previous efforts!