Hi there,
I thought I'd start a follow along thread here.
I've been dabbling a bit with App Installs the past moths, but that just didn't feel right for me. I've put that aside for now and went on with Pay Per Call on Google AdWords. It was the plan to go ahead with PPCall after I got a profitable App Install campaign since I am quite familiar with AdWords.
Due to family issues the month hit off with a very slow start, but I'm moving forward.
I registered with Ringpartner. They've been very helpful until now and got in touch a few times to see everything went smooth.
I signed up for Leonidas' Premium PPCalll blog, which is kinda okay-ish. It's been helpful and not that expensive. Too bad the content is drip feeded and the forum is quite dead.
I'm also trying out SpyFu's tools to speed up things a bit. At first glance, they seem to deliver. Too bad they only have US/UK data.
So what am I doing?
Offer: : Repair my Appliance Now - Home Services
Payout : $3
Geo : US
Network : Ringpartner
Traffic Source: AdWords Search Call Only Ads
Gathered around 4k broad match keywords. I grabbed a domain and made a simple mobile landingpage specifically for this offer, but I won't be using it to drive traffic to.
Started bidding at $2 for a $20/day budget. We'll see how that goes. I'm going for accelerated showing of my ads, but I might change that.
At this point, productivity is my main issue. Need to sort that. Urgently.
Hope to post regular updates here. Feel free to join in with your opinion.
$3 seems like a very low payout for that niche. At your $2 bid, a 50% conversion rate would still give you a negative ROI.
First day of results are in.
I configured the conversions in AdWords wrong at first, which I noticed when the campaign was already running, so I'm looking at numbers there that aren't correct.
I got 15 calls for $ 23.22, which is $ 1,55 per call. Of those calls 10 were long enough. 3 of those were repeat callers, so I got paid for 7.
AdWords Stat: (Overall-1st Campaign - Day1)
Revenue: $21
Spend: $23.22
Profit: -$2.22
The results are better than expected. I upped the $ 20/day limit to see what comes in.
Off to optimize the campaign and seeing where it will get me.
Finding cheaper KW's for lower paying campaigns has it challenges. What we suggest is putting yourself in the mind of the caller. What would they search for if say a fridge broke. "Fridge leaking water", "Microwave not heating up".
The problem with broad match keywords is that you will get plenty of irrelevant calls and your negative list will grow over the time. It's difficult to scale with the broad match keywords with huge list of negative kw list.
Broad match keywords can work if you're willing to spend the money on a lot of unrelated queries at first. Once you add a ton of negatives, your broad match keywords can be profitable for you, but it always depends on the campaign.
That's why it's so difficult to give straight-up answers, because it always "depends" on the particular campaign.
To give you an idea, one of my ad groups with broad match keywords has over 250 negatives so far.
To clarify, are you using Modified Broad Match, or raw broad match?
Lastly, you mentioned that your conversions in AdWords differ from Invoca. Invoca is going to show every call, while AdWords is going to record any call that meets your conversion duration that was set. I would check that.
Little update on this campaign
AdWords Stat: (Overall-1st Campaign - Day7)
Revenue: $45
Spend: $87.69
Profit: -$42.69
I've let it run for a week, but I don't think this is going anywhere. I'm going to pause it and look for another offer to start.
I just can't get why the first day was quite allright. Instead of going upwards after optimising, it all went to hell. Ah well... 
Been sidetracked the past few weeks by other work and family life.
I decided to stop the above campaign until later. Like said above, it might be better to try it out on a ppv source instead of AdWords. It's for later.
This week I put together a new campaign and launched it today. AdWords was giving me a hard time getting my ads online for some reason. The phone number verification wouldn't go through, no matter what I tried. All was good according guidelines and the number was working fine. Last night I decided to just pull the LP url and make a new one, which did the trick.
Offer: : Find a Plumber Now
Payout : $11
Geo : US
Network : Ringpartner
Traffic Source: AdWords Search Call Only Ads
No stats just yet. Upped my bids just a sec ago, because going in with $ 0.2 got me nowhere. Just wanted to go in low this time.
Almost no impressions in the weekend, so increased my bids again.
Maybe my list of KW's is a bit limited this time (+/- 900). Will have to look at that, perhaps.
I've managed to get another campaign online, this time with around 25k keywords. It isn't gathering a lot of impressions, so I guess my bids are too low. AdWords batch upload also rejected around 700 of my added zip codes, so I need to take a look at that. Manually adding them is a pita.
I've raised bits on my plumbing campaign, which is delivering some impressions, but hardly any clicks/calls. I optimised my ad copy to see if QS goes up, but I probably need to raise bids.
I fired up my first campaign again and got that one profitable after a few days. Low numbers, but I'm looking at +100% ROI at the moment. I definitely need to work on that one asap.
I need to get a spreadsheet set up pronto too, so I can have all numbers in one place and do some serious bidding work. Now everything is a bit vague.
Take away from last week: I'm in the green
I'll post details with numbers soon.
i'm newbie but i see you doing great. Would you mind to share if local keywords do good for PPCalls or general?
Are you trying 1KW/1AD per adgroup and making it 100% relevant?
I try to look at my numbers on a weekly basis now. I made a spreadsheet to gather all info in one place.
These are the numbers of the repair campaign.

As you can see it's in the green. I need to get the ROI up and scale it now. Not entirely sure how, though 
The HVAC campaign is going nowhere. Bids are probably way too low and it might not be the season.
Plumber campaign was doing ok-ish, with decent CTR, but conversions were bad. I removed a few "bad" keywords, CTR dropped, but earnings per click are on the rise. I need a positive ROI before raising bids at this point. Off course, that's going to be hard without conversions.