If Cloudkick's product was generating material revenue, they wouldn't have shut it down recently.
My arm chair quaterbacking puts the deal closer to $10M for investors, and maybe a nice bit of earnout.
$30-50mm seems to be the consensus in this and some other places.
$30MM cash was in the 10-K filing.
From the 10K > During 2010, except for the $50 million repayment of our line of credit and cash paid for an acquisition of $30 million, we were able to maintain a consistent level of cash and cash equivalents while growing our business by maintaining our disciplined use of capital.