Did you specifically ASK people to link to your client's site?
NO! We don't ask for links.
For example, how many twitter followers does that account have?
How much time and money was spent in acquiring all those twitter followers?
Not much. The account is an "information only" timeline. The client does not Follow anyone with this particular account.
And assuming that you tweeted about new content, or a specific feature, or something that was (more or less) unique to that site, how much time and money went into creating that unique content?
It's an application designed to attract links. It was originally launched as part of the main site so it is part of the ongoing development process. Social Media is just one of the platforms that was used to promote the application.
If I had the money, I would definitely invest more in it.
I'm not too certain it takes a whole lot of money. It's more of a time issue than anything else.
But to help make a better decision on how much of our time and funds need to go toward social media, I think we need a better understanding of the resources invested in making it a viable way to get links.
Whew, that's a loaded question. We've maintained that Twitter account for 2+ years. We Tweet once or twice a week, strictly informational and promotional. Not an account used to engage Followers like most. We do respond to @ mentions but the main purpose of the account is to supplement the RSS Feed. This particular Twitter account functions similar to a feed.
I've been on Twitter for 3+ years. My very first client promotion on Twitter (2008) got picked up by CNBC, Reuters, Evening Standard, Posterous, Financial Times, Digg and Newsweek. We sold out of product within 1 week of launching the promotion. It was not expected.
For me, Social Media is the shiznit as they say. If you have the right network of Followers, and you've engaged them regularly, they'll take real good care of you when needed. :)