Most online ads today are not aimed for direct sale or click, but more for impression. When you have big budget to deliver hundreds of millions of impressions, it CAN work.
Yes, it's very possible to throw money into a hole with advertising. If you're selling something people don't want, targeting the wrong people, or have ads that don't work with your audience then you'll get nothing back.
Buying advertising isn't a guarantee. Lots of people with little advertising experience would do good to seek out tools and advice to get started.
I think it is too. We finally killed our campaigns on bing, google, and fb - we go with just a few smaller ads on more targeted platforms... and get 10x the results for 1% of the money.
Still nothing to brag about, but money on adwords is definitely money wasted
There're many RTB platforms (hundreds of them) specialized in different ad format and area. For example, some are good at mobile app ad, some are good at video ad, some are good at targeting user behavior. One common rule to perform well in your small-budget ad campaign is to maintain your own site-list (list of website relevant to your product). For example, if I wanna sell a video game, I'll target websites like gamestop and ign exclusively instead of wasting my money on google search ad or facebook. This might not work for big budget because you'll have trouble spending all the money.
Advertise to people who are already interested in your type of product in places they may be looking for something new. Games at Gamestop/IGN etc, specific subreddits, books at goodreads, camping/hiking stuff on hiking boards.
I think adwords is likely heavily dependent on what you are selling. For example trying to make money on a popular travel term is going to be impossible, but selling a niche long tail product with little competition and cheap cost per click might be fine.
Which is kind of scary given that most the major internet services (search, social media, news, etc.) are basing their entire business models around advertising. Would hate to see the state of the economy if that started to dry up.