If you want to waste your online advertising money, send people to your website.
Yes, you read that correctly.
Think about a recent website that you went to for the first time. It's full of information about the company, what they do, where they are, what sales they're holding at the time and so on. But with the majority of people spending less than 15 seconds on a website, dumping all your company glory onto visitors after clicking your ad is just unnecessary noise. Each link to a different section of your page, whether it's to your bio or your latest releases, might as well read "Exit."
You want your ad to do one thing: Convert.
If you are advertising a particular product or service in your ad, there is no reason to show them a load of other things. They're just 40-some ways to stray away. You want to give them the least amount of options as possible, preferably just one: Sign up. A landing page does just that.
Landing pages also help you save money and increase your ROI.
The message in the ad and landing page match, so visitors get what they came for. It can also help your Google Quality Score, which means that your ad is relevant. The higher the score, the higher the ads appear in searches and the more clicks they usually get.
So whatever it is you are promoting and trying to push out, it is in your best interest to get to the point. Lead potential customers to a landing page just for that reason rather than your main site. This is why we create them in Japanese for companies introducing new products and services to Japan, they're concise and they build a database of those who are interested.