I'm wondering what are the pros, cons, and risks of offering a free trial for a product. example. I'm selling home made digital cameras. Of course consumers will look the other way because it is not a name brand or any brand at all. Its coming from an unknown company and will probably think that I sell junk.

If I can create an incentive to try my product first and then buy, would'nt I make more sales? (Of course only if my consumer is satisfied with my home made product).

Say some offer like;
"try my product for free* and only pay shipping. If you like it, you can buy it. blah blah
*free trial last only 30 days, then required to pay full amount of product"

i've always wondered how companys make a profit just by, offering their product for a free trial and make the customer pay shipping. how do they make a profit if the consumer wants to return the product and not get charged the full amount?

so somethings i was pondering about
how would I make the consumer pay the full amount if he/she keeps my product for more than 30 days? or if he or she returns my product, but its damaged? and most importantly, is this even a good idea to do? give me some feed back please.