On Blog search engines

I am currently recieving traffic from 2 blog search engines :

While it is encouraging to see the number of hits on my blog shoot up,I have observed that the number of comments have dwindled.It could very well be an indicator of interest that fellow bloggers have in the content I have to offer but it is also surprising that with so many views per day,its suddenly become so hard to get folks talking.Can someone answer this ?