Are Facebook PPC ads a worth while investment? Or does it depend on the industry?

I can see where, for instance, wedding planners could do well on Facebook, but not computer repairs perhaps?

Does it really matter that your ad gets 10 million impressions a month, but only a handful of clicks? Is that a worthwhile investment in getting business? Or is it more a case of just advertising your company name?

Are people getting more ad-savy now and avoid adverts and go back to using a search engine or asking their friends?

Are companies that advertise a guarenteed so many thousands of impressions a waste of space?

For me, in response to my own questions.
Yes it does depend on the industry and some industries could not live without FB whereas some others could see little return for investing in FB ads.

Its a tricky one, how can you know people actually see the advert rather than it just shown on that page and not been viewed at all?

Users been more ad-savy - im not so sure, i havent really studied much into this. I personally avoid ads - i have adblock installed.

And yes those companies are a waste of space, see the point above about people viewing/not viewing an ad.

Anyone else got any further thoughts or information to share? I'd like to hear them.

And importantly, the original question - Is Facebook a viable means of finding business through paid ads?