Is Viadeo a serious alternative to LinkedIn?

I just joined the professional networking site Viadeo. While it has 35 million members it is strongest in Europe and Asia, which is probably why I didn’t know of the service until recently.

I have added a rudimentary profile to I expect it will take me some time to explore all the features, however I have to ask myself – how many social sites can I realistically be active on?

What is your experience with Viadeo? Is it a real competitor to LinkedIn?