I agree with your sentiment that you should consider the motivations of the author (in any writing really), but it seems like they've done a pretty fair job of analyzing the data.

I think the 12.4x marriage rate is slightly misleading, because if you don't use a dating site then presumably you don't have as much trouble meeting potential partners, and thus are more likely to get married anyway.

But they did round several figures to benefit the match.com, and the statistic is impressive regardless.