At the time the C4 sites seemed difficult. We were using a pure Tengu fleet, and in C4 many of the sleeper waves appear 100km or more from the warp-in point. This is not a big problem for sleeper frigates and cruisers: they come to you quickly enough. But it is a problem for the battleships, which do not come very fast and many of which want to stay at very long range. You end up having to go to them.
For a while we ran primarily C3 sites. But then we got the idea that using cruise missiles and battleships, we could run C4s efficiently. And it is quite lucrative -- much better ISK/hour than C3 sites. We have gradually upgraded our pilots and our fleet so that by now we can run C4s fairly routinely.
There is a downside of running C4s, though, for us: they are finite. This is our home system, so unlike the case for C3s, we cannot just roll our wormhole until we find a system packed with anomalies.
I have read about people farming sites in high-end wspace (C5 and C6). The idea here is to exploit the capital escalations, which evidently do get reset at downtime. As I read it, the idea was that you run the site including full capital escalations (which get 28 sleeper battleships). You kill everything except one ship, ideally some worthless frigate. Then you bring in your salvager and salvage. While it is there, you keep it alive either with remote reps or via jamming out the sleeper. Then you wait until downtime, and voila! You can run the site again. Sites remain around for three downtimes after the day in which they were first instantiated (i.e. first flown to). So you can run each site on four different days, getting more or less four times the income.
Now, in C4 there is no capital escalation. So, that aspect of what I had read about we cannot exploit. But what about the site itself? My memory was unclear as to whether it regenerated. Maybe the whole site regenerated! (This is not actually so, as I found out; read on.) So on that basis, we decided to see if we could farm our C4s.
Since last year, I am fairly sure the despawn behavior of anoms and sig sites has been changed. They used to despawn only after you killed the last enemy; now they despawn... at some point before that. I don't know, and there is no indication of this on Eve Survival. So that's another thing I wanted to find out. We ran some sites a very deliberately.
First things first: we zipped up our system.
|Sleepless Preserver in its native habitat|
After we left, the site despawned, taking the frig with it. Oh well.
Then we ran the other three sites, leaving the last Sleepless Preserver alive. These, we did not salvage immediately. When we finished all three, we came back to salvage. First in was a Tengu to draw fire initially. We brought two Blackbirds running 6 well-amped jammers each; this was enough jamming. Even when we missed all jams once, the battleship did not have the firepower to kill a Blackbird in the few seconds of fire it got before the inevitable next jam hit.
As of the next morning, the three sites were still there. But I did not think to fly there to see what showed up. Then during the day while I was working, someone ran them. I saw this, helpless, on staticmapper. Strangely, the number of kills was 12: 1 then 6 then 5. When I got home, I checked and all three sites were gone. So I could tell the whole sites had not respawned. But what did happen?
After some googling, I found some useful info on the forums. Here is what one Jack Miton, who seems to know a lot about wspace, said in 2012:
as for the respawn mechanics, the only things that respawn are the triggers.The next day we got another Frontier Barracks, and again we left the last sleeper battleship. The next morning we checked, and indeed things worked as Miton suggests. The group of two sleeper battleships which are the triggers regenerated. Nothing else did.
ie: if a site starts with 3 turrets, 5 frigs, 5 cruisers with cruisers being the trigger and you keep it up with 1 cruiser, after DT there will be 5 cruisers at it. frigs and turrets wont respwan.
this is not totally acurate on some sites, for example in a c6 core citadel the trigger is the warden BS but the keeper BS will also respawn.
We left the site for another day until downtime, and this morning checked it again. No change. This is what we expected, but still it was worth looking on the offchance that we'd get more regeneration.
So, it appears that we cannot get very much by farming C4 anoms. In the case of Frontier Barracks, one can get one extra sleeper battleship per day, for three total. However, doing so is fussy (you have to bring in jammers or logi to salvage). And if you get your sites ninjaed, you may even lose (as we did the first time). So it hardly seems worth doing. Most other C4 sites are even worse. However, there is one that may be worth milking: Frontier Command Post. There is a group of three battleships in the final wave. If this group is the trigger, then one should be able to farm this for two battleships per day.
I still do not know for sure what happened the day after our first test. According to what I know now, there should have been 6 sleeper battleships there. My guess is that there was a small gas site, which the interlopers harvested fully, sleepers and gas, so that we had nothing to see.