One of my favourite discussions in business website design is how much information you give free anonymous access to, and how much you withhold in order to get the prospect to give up their contact details. At one extreme, there's the unassailable argument that the more you publish on your website, the more you'll appear in Google, and the more traffic you'll get. At the other extreme, people will claim most vociferously that "if I don't know who the visitors are, they're no use to me", so they limit the information available without registration. The question is then usually: which will get the most leads?
Let's suppose we're after people trying to source large red widgets. Half of these people will type "large red widgets" into Google, and the other half will just type in "red widgets" or even just "widgets".
Website A makes all of its data freely available, and ranks well in Google for "large red widgets". It gets 500 visitors who have typed in "large red widgets". It gets another 500 visitors who have typed in "red widgets", or even just "widgets".
Website B only says it supplies "red widgets", and you need to register to get the data sheet which reveals that it does indeed offer large ones. It ranks as well as Website A for "red widgets" and "widgets", so it gets that second group of 500 visitors only.
Website A's 1000 visitors can all see that the company supplies large red widgets; they don't have to register, or give up any information to find that out. So the only ones which contact the company are those who are genuine potential customers. Let's say that's 1% of them, or 10 visitors.
Website B's 500 visitors can see the company supplies red widgets, but they'll need the data sheet to find out if that includes large ones, and they need to register to get it. Let's say a generous 20% of them are prepared to do that. So website B gets 100 leads, and is the clear winner.
Except it isn't.
Website B is the winner if its job is to get lots of names and addresses for the sales department, regardless of quality. The visitors who have registered are just those people who wanted to find out if the company supplied red widgets in large size. These 100 are really no closer to choosing the company as a supplier than the 1000 who visited website A. If the genuine potential customers amongst them are the same proportion – 1% – then website A wins by 10 leads to 1. Of course, website B has got an additional 99 names for its database, but these are all people who've rejected the company based on the information supplied.
So it's up to you. Maybe, as a marketing department, your job is just to feed the sales department with the names and contact details of as many people as possible who are in your sphere of interest. In that case, try to extract the details from your website visitors as early as possible. Maybe your sales department can turn people who don't think your company is right into customers.
But if you're only interested in customers who want to do business with you now, don't put barriers in their way.