I looked in my account this morning and noticed for the first time that Google is exposing something new in the new AdWords interface:
This is interesting for a few reasons:
- It seems the impressions share report data (IS lost budget in your AdWords report) that many PPC marketing  managers make use of in their daily work is now being exposed in the home dashboard.
- It helps make Google money (notice there's not warning for budgets that are set too high...you're either eligble or you're missing out).
- It will lead to irrational bidding behaviour. The impact may be slight but advertisers will log into their AdWords accounts, see that their campaigns are "limited", and change the way they allocate money, upping their bids on AdWords keywords .
It's important to point out that sometimes a campaign not showing for every available impression is a good thing. Not every query your ad could be impressed upon is one it should be impressed upon; there are often campaigns that only perform well for a fraction of what Google would call "possible" or "related" impressions.