This may not be a popular reply, but I say forget the survey and hit the ground running. You know who they are - give them what they want.

What do webmasters want?

Tools that help them increase efficiently and make money.

so lets take a look quickly at each list.

Joomla List - These guys are going to be a little thick and you are going to need to target products robust in "features" Things that they can come to their own conclusion that it is useful to them. Maybe something like Clicktale (they are with SAS 40% payouts) or maybe keyword discovery or some hosting company with nice specials - (like a VPS) Think almost b2b sounding tools and of course.. . . joomla specific stuff.

Directory list - funny, my spam email is on one of these, ezweb tools or something and the guy slams the email box (i opted in) maybe 5 times a week with whatever swipe copy he can find. he musta have emailed me about keyword elite with the same swipe about 20 times already lol (is this you!!!)

Is is effective? Well not for me, because I am not your target market, however I suppose this guy figures that all these people are just dropping their email to get a "free link" and therefore basically anonymous and unfocused and might as well slam the list until they convert or go away.

Its a strategy, though one could also take the same opportunity to build yourself up as a cult of personality and turn it into a weekly newsletter that you interlace useful content along with relevant affiliate links ( though I suppose that takes alot more work than just pasting swipe copy and burning the list)