We’ve known for months that Radian6 Technologies Inc. was a great deal, but we’re only now understanding just how great a deal it was.

Canada’s Venture Capital and Private Equity Association on Wednesday awarded its Deal of the Year to the investment by venture capital firms Summerhill Venture Partners, Brightspark Ventures and BDC Venture Capital. The three firms invested a total of $9 million in the Fredericton group that analyses social media posts. When Radian6 sold out to Salesforce.com of San Francisco this year for $326 million, the VCs pocketed $205 million.

The Venture Capital Association, known as CVCA, issued a statement that included two ratios not seen before that demonstrate how eye-poppingly great this deal was.

First, the Radian6 deal had an internal rate of return – the key ratio in determining the annual return for investors – of 142 percent.  How good is that? Press reports say that the top quartile of American VC funds (admittedly entire funds, not individual deals) now book IRRs of just under 10 percent. So, if all your deals produce an IRR of 10 percent, you’re better than three quarters of your competitors – and Radian6 exceeded that benchmark performance by more than 14 times.

The second indicator is the total return of 22.8 times. This is self-explanatory: for every $10 of equity they bought, they got back $228 after three or four years, which is likely better than your RRSP has performed lately.

Let’s provide a bit more context for the Radian6 deal:  If you look at the last seven CVCA Deals of the Year, there’s only one that tops Radian6. In 2007, a Victoria, B.C. biotech called Aspreva Pharmaceuticals sold out to a U.S. company for US$915 million, which gave VC backer BC Advantage Funds a whopping IRR of 272% and a total return of 23.4. times.

Other than that, there has not been an award winner whose numbers come close to Radian6. The closest was the 2007 prize winner, in which GrowthWorks earned a 134 percent IRR on its investment in Galleon Energy. The returns in that deal couldn’t match Radian6’s, and I’m just snotty enough to argue that energy plays shouldn’t be included in awards for VC investment.

The complete list of Deal of the Year winners is included below. (I only went back as far as 2004 because the winner that year was a buyout, or a debt-laden purchase of a mature company. It’s a different beast than a VC investment, and in subsequent years the CVCA gave two awards, one for VCs and the other for buyouts.)

The award aside, Radian6 has produced and continues to produce tremendous wealth in the region. Quentin Casey reported in this month’s Progress magazine the company has 350 employees, including substantial bases in Fredericton, Saint John and Halifax. They’re still working here and last I heard Radian6 was still hiring. And Andrew MacDonald pointed out in today’s AllNovaScotia  that 12 New Brunswick investors received an estimated $68.4 million in payouts from the deal. That means a dozen Atlantic Canadians with a history of investing in startups have tens of millions of dollars, which bodes well for the next generation of startups in the regions as they will likely invest again.

There’s one final inescapable conclusion to draw from the Radian6 deal. It was the last deal BDC did before shutting its VC operation in Halifax, and the federal institution has never had a better deal anywhere. If you found a nugget of gold in San Francisco in 1849, wouldn’t your inclination be to stay in the area and dig further? It’s in BDC’s interest to take another look at this region. It gained tens of millions from Radian6. It knows there are good opportunities here. There’s a new Regional VC fund looking for investors. The logic is painfully obvious: BDC should look at investing in the regional VC fund.

CVCA Deals of the Year, Venture Capital Segment