If your company is having difficulty recruiting and retaining the talent your company needs to survive, succeed, and thrive, there is ALWAYS a reason, and the most common reason is that you not offering to pay enough money.
If you are attempting to pay significantly below the going rates, and your company is a "me too" outfit, doing the same thing everyone else is doing, you're going to have trouble. If your company is an outstanding place to work, doing SERIOUSLY cool stuff, you MIGHT be able to pay a little lower - but you are going to have difficulty even then.
If your company is paying going rates, but is known in your area and industry as a terrible place to work, you are going to have serious recruiting and retention problems.
And there's this. If your company is a great place to work, doing seriously cool things, AND is successful enough that you can and do pay ABOVE market rates, you will have your pick of applicants. (Your competitors will hate your guts, however, and will do anything they can, legal and otherwise, to put you out of their misery.)
Yes, it can be appropriate to offer "recruit-a-friend" bounties, but it may say something not completely good about your company when you do it.
When your employee talks to his friends, what is he going to say when the friends ask about pay scale, raises, benefits, working conditions? If your employee has to tell your friend that there haven't been any raises in three years, and they don't expect any raises at any time in the foreseeable future, if your employee has to tell your friend about high rates of mandatory free overtime, if you have a local reputation for boom-and-bust hire-and-fire cycles, offering bounties is probably not going to do you a lot of good.