PPC advertising can be both a long-term and a short-term strategy. This is because you can control your campaign at will. It all depends on your budget. If you're profiting from your campaign, you can leave it running indefinitely. If you're on a tight budget, you can run the ads for as long as your budget will allow, then pause your campaign at any time (and, of course, you can turn it back on, too, when you're ready).