From August 2014 through early April 2016 American warplanes haves launched over 11,400 sorties against ISIL (Islamic State in Iraq and the Levant). So far 67 percent of those sorties have been against targets in Iraq with the other third against Syrian targets. Each sortie has cost nearly $600,000. Most of the targets were over 5,000 buildings and fortifications used by ISIL. Nearly 3,000 vehicles were destroyed and more than 500 industrial (mainly oil production) facilities were hit. Increasingly these attacks are in direct support of Iraqi troops fighting ISIL and Kurdish troops doing the same in Syria. Until late 2015, when more Iraqi units were provided with ground controllers to call in attacks, warplanes hit targets found via satellite, aerial surveillance or reports from people on the ground. The availability of more ground controllers makes it possible to hit more enemy fighters in contact with friendly troops.
Unless you were using ground controllers the biggest problem was not finding targets, but finding the right targets and hitting them when it would do the most damage to ISIL and several other Islamic terror groups involved. Hitting buildings or fighting positions after the enemy had departed (or before they arrived) looked the same from an aircraft (or spy satellite) but was quite different for the enemy and those they were fighting. Thus having air controllers with the friendly troops on the ground was important. Unfortunately it was not possible to do that with most of the friendlies until late 2015. Before then most Iraqi Army units were not reliable or competent enough to assign Western air controllers. The Kurds and a few Iraqi Special Operations units could be relied on to protect and effectively use air controllers but the Kurds would not operate outside their traditional homelands in northern Iraq and northeast Syria. There were very few special operations units. Iran supported Shia militias and the Shia brigade from Lebanon refuses to work with Western troops or air power. Now there are more special operations troops and ground controllers and more Iraqi units competent enough to use close air support.
Over 50,000 sorties have been flown so far and most are support (reconnaissance, surveillance, control/AWACS and aerial refueling). Extreme measures are taken to avoid civilian casualties, which means a lot of military targets have to be left alone because ISIL uses civilians as human shields a lot. For this reason it’s important to have friendly, and competent, troops on the ground to positively identify enemy targets that have a very low probability of causing civilian casualties if hit. For that reason more and more armed UAVs are being used as these involve less risk of civilian casualties. Since late 2014 the air campaign has killed over 10,000 Islamic terrorists (mainly ISIL) and caused major morale problems for all Islamic terrorists in the area.