Star Alliance's marketing department is savvy and I don't just say that because I know the folks in it...
Take a look at the latest Star Alliance Gold advertisement--
What I love about this commercial is that it simply yet accurately and convincingly shows the alliance-wide benefits of having gold status. As upgrades dry up on United, at least I am closing in on MMer status and with that will come Star Gold status for life (for me an a companion).
I spent a lot of time in Star Gold lounges last week--Los Angeles, Honolulu, Guam, Tokyo, Singapore, Rangoon, and Bangkok--and I find lounges quintessential for working/eating before a plane trip. That truly is the beauty of global airline alliances.
But there are other important perks too, which the commercial nicely highlights. An extra checked bag, priority check-in, security, boarding, waitlisting, and baggage delivery.
With gold status to be had for as little as 20,000 miles (with Aegean Airlines), it makes no sense for a semi-frequent Star Alliance traveller not to have it.