When you indeed really need the money it can be worth it to borrow some bitcoins bit I still would never do this if I where you.
Its just not worth the risks that you have to take.
bitcoin borrow quite difficult, I suggest you borrow bitcoin when there is a business that is highly likely to give you an advantage, because then you can replace them quickly
Poloniex already offers their lend service,but you can offer any rate you wanna,there isnt a minimum fee to charge soo usually the loans there are around 0.03% meaning almost nothing,if they set the fee to atleast 1% or even 2% then rates above could be set by the members would be great.I doubt any reputable system will come lending money to anyone use where they wanna as btcjam and similiars programs,letting some scams build reputation and then run away.