If it's digital (no cost to us), then usually you contacting me in private would get you a free copy. HOWEVER, I'd first want a quick 2-paragraph intro to who you are, your sites, your experience, how you plan on marketing.

At worst, it gets me an introduction to an affiliate so we build a better relationship. At best, it's a win-win... I learn about my affiliate and they get a free copy for personal use and as review for their promotions.

So with digital, the above is pretty much all I look for.

For physical, I'd be very interested first in meeting you. Chances are if I already know that you're established in the market... then, getting you a copy likely won't be an issue. Otherwise, you'd have to "elevator pitch" me on why you feel you have the distribution network in place to produce at least a handful of sales in the short term.

Frankly, I'd say if you're honest about your intention to at least thouroughly review and consider the product (afterall, you may discover upon review that the product isn't what it's presented as or is junk), but as long as you're serious about looking into it... you'll be fine with simply contacting the merchant in private. Not all will jump at giving out a copy, of course, but it's also a great way to slide your name in there fore them and briefly "network" for possible future JVs etc.