In all your experience with lead scoring did you find there was a difference in the score based on people who supplied more information vs. people who only supplied an email address?
I can kinda answer that... the way scoring works, for the most part, are not going to get a score without a name.
I would not pay for 3rd-party leads without good contact info, based on the premise that reasonably low-funnel "surfers" are more than willing to provide good contact info.
While it would be "nice" to take a shot at everybody with a hankerin for some new wheels, logistics come into play here. Take Omni, for instance. MB pushes these "preferred" (aka "garbage") 3rd party leads on us.
I tried to explain the aggregating system to a few people here when explaining why Omni was probably not a good investment. I told them to do a search for something stupid, like "Cheapest Mercedes in the World." Of course, in the paid section, we found and clicked a site that said "Find the Cheapest Mercedes in the World." Filled-out the form, and 2 seconds later, a Benz lead showed-up from Omni. This is the crap we pay for, and these
have name and contact info. Can you imagine the crap they'd send you if even a name was not required? Ooof....
3rd-party leads, at best, need a lot of attention. Now, gathering email addresses to automatically filter into a prospecting program -- that's a different story. But probably still wouldn't pay for them.