I've noticed a number of companies raising significant amounts of money, that are building products related to messaging, instant messaging, and related. At first, I didn't get it. IM services and IM aggregators have been around for a long time, and have historically had a tough time generating much in the way of profits. So it's not a new model, and it's one where historically even the leaders in the field have had a tough time making much scratch.
Thinking a little more about it tonight though, I think I am starting to understand the situation a bit better. I saw the results of a research study recently that attempted to describe the components of social networks like myspace and facebook that people truly and consistently value. A large part of the sustainable value that social networks provide is the management and maintenence of what is in essence an "address book". Social networks have trumped email, for many people, in their ability manage a contact list / address book, find people to ad to this list/book, and provide a broader set of interaction / messaging options. It's easier to find people you know, add them to a list, and message them in any number of ways.
And a messaging / instant messaging platform could provide the same functionality, if built properly. So I think a lot of people see a bridge from a messaging / instant messaging platform, to a social network, or some hybrid of the two. And are funding messaging platforms for that reason -- because they believe they can be a viable competitor to social networks, if structured properly. A messaging service seems like a good starting point if one was trying to build a superior social network -- or build some related service that could trump the existing social networks.