I am running a tech blog and i am getting CPC around $0.15 to $0.25 CPC these days while normally i get $0.25 to $0.35 CPC. Is it normal? I previously used 2 ad units on my site and i increased it to 3. Is it the reason because i heard that increased in ad units might display more low CPC ads.
Yes it's normal, don't worry about it, and never talk about today's earnings as they're not accurate.
The CPC depends on the content and the place where we get the clicks from if this content is within some high competitive niche and if you get the click for US or UK then the CPC will be high or if it some other geo location then it will be usually low in comparison with the above stated locations. however, even i own a technology based website and the CPC is the same, becouse technology is a high traffic niche. for high CPC you should try some thing in insurance or education niche and which should be researched for the above mentioned locations.