Know-How Exchange : Advertising/PR

Here are some places to get data:

https://www.emarketer.com/SiteSearch.aspx?arg=Advertising%20Spending%20Reve...

https://www.marketingcharts.com/interactive/smb-ad-spending-undaunted-by-ec...

https://palore.wordpress.com/

https://www.bmighty.com/blog/antenna/archives/2008/08/smb_ad_spending.html

It's not clear why you want this information. What will you do when you have it? How will it affect your marketing decisions?

What you might want to do is check the cost of a top 5 listing for the right keywords in Google AdWords along with the number of exposures you can expect for each. While that won't give you a specific answer to your question, it will let you know what it will cost you to be competitive in that market. (I'm assuming this is where you want to go with your original question.)

Separately, it's not clear if you want to measure total spending or just direct online advertising. For example, what about the cost of a good landing path, metrics, constant testing, etc.? Do you intend to include those kinds of things?