For those email marketers using Silverpop's Share to Social feature, which allows you to share your emails into recipient's social networks; it can sometimes be difficult to know which networks to use - after all you don't want to list all of them when they may not be big enough or from the right demographic. That email preview window is not infinite in size and so making optimal use of screen real estate is a must.

There has been a bunch of informaiton released recently which shows the reach of social networks today.

First up, from Comscore; data on the Top 10 Social Networking sites in the UK:

Secondly, it is unsurprising that younger audiences are more engaged today;

Finally research from Ofcom shows that it is amongst the older audiences that social networks are experiencing the most growth. 25-34 years olds on Facebook increased from 40% last year to 46% this year; whilst 35-54 years grew the fastest - up 8% to 35%.

(hat-tip to ClickZ for pointing me to the data)