Carts are the key to solving the "generational" issue (aka old people). Carts allow them to just sit and wait, while counting time. The reality is that most large cities have for years had witnesses at various stops for approach work, but this is much easier for a senior to do. Its really just busy work. I've had to pleasure of watching several carts for the past year, and the success is minimal at best. I'd argue the workers are more disheartened as the likelihood of bad apostates talking to them is greater. But the vast majority appear to just enjoy sitting in a chair (or motorized chair). This is really nothing new, its just that they added a cart, and you can just sit on your arse and do nothing.
In the circuit I was with, we got 2 bible study requests since JW.borg has been active, a sizeable circuit at that. Still if you did the math and said 1,000's then its still a very small number considering the publicity.
I watch the analytics on the website and its pretty flat. Really with about 800,000 page views daily and 8,000,000 witnesses its actually pretty bad. I like one site that says the traffic is worth about 1.7 million dollars. http://www.freewebsitereport.org/www.jw.org
The real question I have is if the risk of lawsuits is greater for door to door or from the carts?