What are the best sources for finding competitor PPC spending by category?

[JoeAmadon]

Can anyone provide sources for gathering paid search advertising spend for competitors, preferably by category?

Thank you.

[Cyle]

SEMRush is a good source I use; it will show you the sites estimated expense for PPC spend.  I don't know if it can show you how much your competition spends based on category.  I have never tried to figure this out with their tool.  Hope this helps.

[DavidKonigsberg]

spyfu.com and keywordspy.com also gives you spend for competitors and allows you to see other competitors aswell

[JoeAmadon]

Thank you for the advice, gentlemen.

[CarlLarson]

Unfortunately none of these tools give accurate info. I know because I compared against my own campaigns. Had a SPyfu paid acct for years and it is a useful tool, but not for quantifying adspend.

This was kind of helpful:
http://searchengineland.com/tips-for-spying-on-your-ppc-competitors-89988

Any other advice out there?

[Matt1]

I as well had a Spyfu account. I wasn't impressed. The numbers are pretty inaccurate. The best you can do is get a very ballpark range of spend. However, I'm not sure there are bulletproof sources for this information outside the walls of the paid advertising provider anyway. I could be wrong though.