I just started an app install campaign and am not really seeing any traffic. I upped my bid to $3 for CPA but still have many keywords saying "Low bid or quality score". I have a free app so upping my bid anymore will result in a negative ROI ($3 seems a bit high even). That being said, would there be value in upping it plus my CPC/CPM and letting Google bid manually for a few days to get my quality score up and bring some traffic, or would that strategy just end up with me spending more than I want?
It is advisable to start with a little budget. You can learn that way. Later, you would be able to optimize your campaign.