Like all forms of marketing you need to make sure that the following are all in place and aligned.
Market, Message and Media. If you have a great message but to the wrong market then your campaign will bomb e.g. Targetting pensioners with offers a all you can drink nightclub offer will bomb while the same offer to students could be a great success.
In this way people often blame the type of media they are using, saying things like direct mail doesn't work, when in fact if you look more closely then perhaps the message was week or the market poorly targetted.
Therefore I'm not sure if there is much value asking if a type of media is good and whether it got a good response. What could bomb for one offer and market could be hugely profitable for another.
The only way to reall see if this type of media will work for your offering is to do the following.
Determine who your target market is.
Test an offer on a small scale to that target market and measure the response.
If the results are favourable then do more.
If the results are not favourable then tweak either the message, market or media and rinse and repeat. Simple huh?!
Anyway if you think this media reaches your target market then why not approach the owners of the screens and see if they will let you conduct a test. Spend a few hundred on a test and make sure you have some kind of tracking mechanism in your advert so you can see clearly the response generated.
As with all media don't commit to a huge amount upfront without conducting a small test first. If they wont let you do this then move on to something else. If you buy 10,000 impressions and get no leads then buying 100,000 is not going to give you much of a different result.
Hope this helps.