Google Webmasters's Dashboard gives you a big number which is called impressions, and that I've seen in Google Analytics. By definition, it means the total number of times your site has been become eligible for SERPs.
I just don't have an idea how to interpret this number, and how much its increase or decrease mean to me, because I can't compare it with other websites.
I mean, if the impressions of say site
a.com are 150,000, and the impressions of my site are 50,000, then maybe it implies that I need to triple my efforts to reach the impression rate of
a.com. Yet, by seeing 50,000 impressions alone, I have no clue at all of how to interpret it.
Is there any service or other way to know about the impressions Google gives to other sites?