What's the best approach to scale in adult?
Finding a profitable campaign in a single country and then translate the landing page/angle/banners and scale to other countries testing new offers for that GEO in a single placement?
What's your approach?
Buy other GEOs. (you mentioned that)
Try other sources (although there is not too many "quality" adult ones out there than the usuals most of us know about)
My advice:
You can also buy flats depending on the offer(s) that are killing it for you. So if you know Pornhub Mobile Footer kills it on TJ's bidding system, you can go ahead and buy it in bulk and get a guaranteed mass amount of volume. The downside to this is if you don't negotiate correctly or have an in with a rep or so, you could be buying this traffic at a premium CPM higher than you paid for on their self-serve bidding system now to secure bigger volumes for scaling. But you also need to make sure you're ready to take on a mass amount of traffic coming to you from all sorts of GEOs, so your funnel and tracking needs to be on fucking point. (Usually tier 1 countries making up 50-60%+ of the traffic depending on who you're buying from)
Hope that kinda helps?
Cheers.
Also, if you need help getting in contact with those who could sell you flats (bulk amounts of traffic), hit me up on Skype and I'd be happy to introduce you.
Yup, you can basically scale to a different GEO or to a different traffic source. The first step should be to scale to more sources and to stay in the same GEO. This is because people in different geos tend to have a different taste when it comes to woman. So you need to alter your LPs and banners when moving to a different GEO. The angle itself might be transferable, but you dont want to use a white woman when targeting an Asian country for example OR a black woman wont work in GEOs with low % of black population.
Buying FLAT as theeroly suggested is an option too, but sometimes it brings more negatives than positives - they usually dont give you the option to set some CAP, so the low looking CPM price will not be so low anymore due to lower CTR. To get the best price, you need buy mixed global traffic, so you need to have tested funnels in all the major GEOs or you're gonna loose royally. FLAT deals are done for fixed periods of time, so if you loose some good offers in the middle of the term ... that can be painful. These are always managed campaigns more or less, which means long wait for banner approvals and sometimes the absence of some admin section. Its also possible to target this better, but every bit of extra targeting drives up the price ... These days, when proper targeting can dramatically increase the ROI, I prefer to stay on self server sources.
Im only aware of one good platform for flat deals - traffichaus.com, but lately they are weird too - anything I tried lately, they never delivered the agreed volume, so instead of a 10 day test, I ended with a full month due to lower volume. Since they buy the placements from several pubs, the quality is also inconsistent even when its from one site... not sure what they are doing over there.
To get back to the original question, I recommend this when scaling :
1. Start on a limited amount of premium placements,
2. If they work look for more premium placements on the original source and then on other sources,
3. Play with the cap and bids,
4. Go to RON
5. Enter more GEOs
Yeah buying a flat, if you're not ready to properly convert it you will get KILLED since there is no freq cap on there, your CPAs will go through the roof and you might even age a few years in the process. Trust me, I have.
You will need to have a badass tracking / funnel in place to cap users and serve them different offers, etc. Thats basically the game a lot of the smaller traffic resellers also play when buying traffic from TJ, etc and re-selling.
I did something yesterday and it's working better than I expected: Created a campaign and selected every premium NTVA placement under 100.000 impressions/day (in the bigger ones I created separated campaigns). Of course I could've tried RON, but I have to admit: I don't have the budget and balls required for it yet. 
Awesome tips from Matuloo and Theeroly!
In Adult, are you using Pop Traffics or Display traffics?
Just throwing our hat in the ring... Kimia, is a performance adnetwork with 10 years of experience in the adult industry for mobile marketing
... In fact this is our 10 year anniversary!
If your interested in learning more about us, visit our threads:
http://stmforum.com/forum/showthread...ighlight=kimia
http://stmforum.com/forum/showthread...ighlight=kimia
Or contact me
email: marina@kimia.mobi
skype: mlopezarranz