There are two reasons why Google might limit your impressions (apart from the need to test the inventory of other advertisers):
1. Your daily budget is too low. This is simple to diagnose and fix. It’s possible to double or even triple the impressions on a profitable account simply by increasing your daily budget, even raising it significantly above your current spend. With this, you need to exercise some caution. How profitable are your campaigns? What can your marketing budget sustain? Answer those questions, and you can raise your budget and impression share accordingly.
2. Your Ad Rank is too low. You can improve this by giving attention to three things:
- Ad extensions. If you’re not using them, then try some site links, callout extensions and call extensions.
- Quality score. Google looks first at whatever campaign is running the highest volume. If the quality of the ads and keywords there is poor, your impression share will suffer. If you’re showing a Quality Score of five or below, work on improving it.
- Maximum bid. If you need to bump this up to improve your Ad Rank, do so incrementally. Review your max bid every day, and don’t raise it more than you can afford or sustain. It’s better to have a low impression share in a profitable campaign than to have a high impression share and be losing money!