This is a simple non-revolutionary marketing strategy which has worked over and over for the last 100 years. It has legs and I see no slowing down at all.
I was recently watching a tv program regarding prohibition, and the show discussed the history before and after Prohibition. It spoke of the amazing competition between breweries and bars prior to the Act, and marketing strategies the various bars used to get customers.
The one that struck me most was very simple, "Get a free lunch". Imagine that, they offered something for free, but in return the prospect had to do something for the advertiser. They had to come in, sit down and have lunch.
Sounds like a no brainer for the customer, and it was. Of course, while they are at the establishment, the idea was to sell them on a few drinks, where the real profit was.
The point is nothing has really changed and what worked 100 years ago still works. This is a classic example of the 2 step approach, and you can institute this strategy in everything you market.
All you need is some bait, which I might refer to as an "offer your prospects cannot refuse". This bait is likely not refusable because it is either free or no brainer cheap compared to its value. Once your prospects take the bait, you now have a lead.
This is step 1. Step two becomes much more focused in how you approach this prospect. You already know you have a captive or interested prospect, so you know very well your likelihood of closing him or her is substantially greater than a cold prospect. That means you can invest in very focused and far more expensive follow up material or salespeople than you could simply going to a cold audience.
The beauty of a two step approach is it forces far more people to raise their hands to be identified as true prospects, be them right now prospects or future prospects, because it makes it easy for people to respond and get that no brainer offer in a very stress free and unthreatening manner.