Well as long as you are allowed to give it away then you should give it away. This is a good prospective content locking scenario where you would offer the product to your folks for opting in to your email list, and/or completing various cpa offers.
If up to this point you have only been using CPA banner ads to get clicks and conversions, then moving into a content locking situation with offers that can be incentivized(are compliant with network requirements) is a great way to earn more money.
If you have already been content locking and using CPA offers in this manner, then you will be unlikely to find that actually giving away the product increases conversions unless you are using the same leads to build your own internal list. In this situation since these guys know you do giveaway stuff ... they might be more inclined to convert on other offers down the road.
If not using incent offers - in my opinion the whole content locking angle goes to crap for a monetization factor unless you can find something legit to stick in there, because advertisers will begin to quickly realize your leads don't back out, and you will start getting blocked from offers and eventually banned from networks and blacklisted in addition to losing revenue. So with content locking - it's always best to make sure your promotional strategy and content are fully compliant and you are only using incent offers.
If you do go with giving the stuff away, don't forget to implement a way for you to gain this person as a subscriber to your email list. This type of prospect knows exactly what to expect from you in the future, and they are very likely to convert again or even possibly buy something from you such as "1001 best giveaways," or other types of products/giveaways. Most people do this with a standard fulfillment process where the person opts in to the list first, and then it's your follow-up series of emails that leads them to the product for download. This way, you get the lead first, and then they get their product.
4k prospective lead members per day are slipping away from you right now while you try to figure out to monetize them. If I were you ... I'd start capturing them now, and figure out how to make that money as the list builds. You can even ask them directly what they want, but not until they are your list members. Bring them on board man!