Talk about a vote of confidence. Less than a day after Facebook poached another executive from Google, the social network has gotten a $40 million nod from one of its key investors.

Hong Kong businessman Li Ka-shing raised his total investment in Facebook to $100 million, up from a previous commitment of $60 million.

But the investment doesn't just point to vitality at Facebook. The influx of capital could highlight a new direction for the social network, and perhaps the wider interactive marketing business.

"Facebook is doing very well and we could have some synergy between the 3G services of Hutchison and Facebook, so the customers could use Facebook on mobile phones," Li said.

Li is the chairman of Hutchison Whampoa Ltd, a holding company that owns mobile phone operations throughout the world.

While mobile is still considered an emerging platform, Facebook, like all the other major players in digital, has been trying to figure out how to get in on the ground floor of what many believe could be the next big thing. Earlier this month, Google reported that it had hit a "watershed moment" in terms of mobile internet usage.