That depends on your business and where you are right now. Anyone that says you MUST without talking to you and understanding your business is talking Hog S###.
First off, if you decide to do it, it’s measurable and quick. You can test thoroughly with as little as £100 and should know really quickly if its working.
You should have tracking in place, so you know that X clicks are needed for Y clients that bring in £Z worth of business. Tracking is not too difficult, Google Analytics will have you covered in most situations. It’s easy to add to your website and above all it’s free.
It’s quick, within 10 minutes you can be testing. You can pause or stop at any time and see results fast.
It can easily tie in with other channels, for example if you get a user from Google Ads to your website you can then send them related adverts on Facebook. This means potential customers / clients can see your message on loads of channels.
Generally speaking you only pay when someone clicks! So unless you are getting advanced you don’t need to worry about incurring large bills.
You control the budget, so there is no fear that you will suddenly land yourself with a massive bill. It’s often best to start small, with low budgets and slowly increase as you see results and refine.
It’s not just Google, you can reach a different set of users on Bing. Each PPC provider has different demographics, so whilst Google maybe the major player, generally older users stick with using bing as it ships as the default search engine on new PCs. So these older less tech savvy people can be much cheaper to get in front of. That does not mean they are not valuable, in fact they can be more profitable. Just keep an open mind.