You are asking a very broad question. It is going to be very different for every brand. It really depends on each brands goals. A company might find that they get a better return on advertising spend when partnering with a Twitch streamer than running a YouTube ad, but for a different brand it could be the complete opposite. Each brand will have to test their own strategies to discover what works best for their company.

Do you have a website where I can see the services that you offer? Without knowing much about your company Google AdWords may be a good platform for you to advertising on, but I would have to know more about your business to give a better answer.

I believe that Facebook Advertising may be a viable option for you. You can target national automobile dealers association members as well as those who work at certain automotive dealerships. Facebook has very advanced targeting and with a little focus you can find your target market on the plaform.

Why do you need a high-volume of traffic is my first questions? If you are running a media company and need more views for advertising purposes than wanting low CPC is a good goal. However, if you are selling a product or service the CPC doesn't matter as much as the ROI you are receiving from advertising. I have been able to generate CPC's as low as $0.02 on Facebook going after a highly targeted hiking niche. However, you need to have a good niche with a decent size to generate that low of CPC on Facebook.

In my opinion your cannot make something "go viral" organically. It is something that happens naturally and with a great marketing campaign. There are more than 1.5 million apps on iTunes and the chances of your getting found are minimal. You need to create a marketing campaign that uses paid traffic from Facebook to spread brand awareness and increase app downloads. I would like to ask how your Facebook page has 24,000 likes, but your app only has 300 downloads? If did not pay for this "likes" then there is a way where you can turn those fans into app downloads.

Depending on the advertising platform and your budget, you can run multiple highly targeted campaigns at the same time. The more targeted your campaigns the more profitable they will be. For example, Campaign A can target only those in US, while Campaign B, can targeted only those in Australia. Each campaign has its own messaging, landing pages and specific ad copy to that region. Campaign A and B can both run at the same time as long as you have the advertising budget to so, if you do not then I recommend choosing your most profitable country first.