The travel darling of Silicon Valley and the poster child of a social media-led Hollywood have united - Ashton Kutcher has invested in Airbnb and joined as an advisor.
Only in Hollywood, some might say, but the reality is that Kutcher is well known in tech circles for his enthusiasm for the world of startups (with Ooma, Katalyst Media) alongside his high profile marriage to actress Demi Moore and becoming the successor to Charlie Sheen on hit US show Two and Half Men.
According to Airbnb, in a starry-eyed blog post yesterday:

"With his incredible wit and personality, Ashton Kutcher has shown the world the power social media has on emerging brands and in developing strong, passionate communities."
Kutcher has invested an undisclosed amount in Airbnb and will become a strategic advisor to the company.
Whilst on the one hand having a startup fan and well-connected individual involved in the business has its benefits, sceptics may wonder whether the partnership is actually more of a PR exercise (Airbnb can probably ask any number of Valley investors to pump in money these days, such is its profile).
But this is where the worlds of celebrity, social media, money and the web now collide - if Kutcher mentions Airbnb just once on Twitter there is a fair chance that some of his 6.8 million followers will be curious to see what he's going on about, especially as Airbnb has international ambitions.

"Airbnb has pioneered an industry and broken new ground as a trusted community marketplace where people from all over the world can discover and book unique spaces from people anywhere in the world. Now it’s time to expand and time to bring our concept to communities on an international scale."
Less well known is Kutcher's involvement in that other starlet of the West Coast in the US, Hipmunk. Kutcher was one of the original investors in the flight and hotel metasearch startup, but has not taken a board or advisor position.
Co-founder Adam Goldstein says he speaks with Kutcher "two or three times a quarter", primarily as someone to bounce ideas off:

"We took his money (unlike others we turned down) because we liked the way he thought about branding, positioning, and marketing. He's got a lot of experience and success in these areas--and in particular through online channels, where we've found most of our most avid users."