This introduces yet another source of sample bias. This distribution actually pleases me, since it means we have results from users of many different systems. Obviously, however, the quantities are too small and sample bias too significant to break out results by vendor.) nbr responses vendor 8 Marketo 6 Eloqua 3 Genius.com 3 LoopFuse 3 Pardot 2 Market2Lead 2 Treehouse Interactive 1 eTrigue 1 Vtrenz (Silverpop) 7 No Response 36 Another intriguing bit of contextual information is the deployment date of the systems. Again, we have to consider sample bias.