Search traffic is bottom of the funnel where people express intent. If there is existing demand for your service, than search traffic is valuable. If there isn't demand but there are competitors, bid on their brands, if you are in a new industry with no real competitors you probably need a reality check but search is not where you will find users.
Because search is bottom of the funnel and demonstrates explicit intent it is the most expensive traffic out there. It definitely works though and anyone who says differently just gave up before finding profitability.
I tell my clients to invest $5k in search the first $1k will return $500 (lose $500). The second $1k will return $800. The third will break even, the fourth will show a 25% profit and the last $1k will find profits you can scale.
If you don't go in planning on losing a bit to find what works (or go in with a site that won't convert) it won't work. If not there is no reason it can't work.
All that being said...Facebook right now has the most robust targeting in the advertising world short of massive enterprise DMPs. Milk it for all its worth if you can.
Read jonloomer.com to master Facebook ads.
3rd was developer focussed online magazines. I would also try retargeting (from Google) in conjunction.
Google ads works best when you are really the answer the searcher was looking for -- if you have search terms that you think you are legitimately the top result and the competition for ads isn't insane, it's worth a try.
You can go in a little and measure the results for all of these choices.
The price of a user is defined by the following formula [0] : CPU = CPC * (C / U)
Google AdWords gives you the CPC and if you have a Google Analytics set up you should be able to know the C / U ratio. That will define how much you have to pay to get a user using Google AdWords.
For the C / U ratio to be precise you should use only the organic search numbers (people coming to your website from Google after a search) because it is closest behavior you can study.
[0] : * CPU : Cost per User
* CPC : Cost per Click [on ad]
* C : Click [visitor comes on the website from ad]
* U : User [visitor becomes a user after he clicked on the ad]
Before going down this process you should know how much a developer sign-up worth to you. You can always buy growth, but you need to know if you can buy growth profitably. Generally look to get a short term value plus a life-time value calculate ROMI. It wont be accurate but do the best you can.
Between Google and FB, I've found Google search is the regular winner but the ROI gap is narrowing these days. There's some good hacks you can use to access your audience cheaply if you get creative. I would recommend you trial display as if done well this could provide better results than search (where most companies go first).
There's a pertinent quote for new products: "A great ad campaign will make a bad product fail faster."
Make sure your monitoring not just sign-ups, but how long people stick around etc.
Best of luck.
https://www.hackerearth.com/recruit/source/ for instance, at the bottom under past challenges has a lot of spelling and grammar errors. Hire a US-based copy editor.
Also why not advertise on careers.stackoverflow.com? Or stackoverflow itself in certain markets, is probably more cost effective and targeted than your google ads.
You'd be surprised at how few people click them. If I wasn't at work right now I'd love to go into how some of these people trashing search are flat wrong. Showing up in the organic search results for even a relatively lame search term can increase your views/impressions exponentially.
User acquisition, though, is something that goes way beyond just putting up an ad or getting into search results.
I'm not sure about stack overflow ads. Hackerearth also helps developers find jobs and that might a conflict of interest for stack overflow careers.
I will personally reach out to some of you folks. This has been really useful!
LTV = Lifetime Value of your customer
CAC = the customer acqusition cost
Since the CPC on AdWords are quite high and finally the resulting CAC will be also quite high (still depends on your conversion) you need a product with a high LTV. I don't know how much LTV you try to achieve with HackerEarth but it should above be $100.
Cheaper channels: affiliate (so CPA based deals) or SEO
To tell you that it works. I actually recently signed up on your website and I found you through your notes section. I think it needs some SEO work..
Also try to be more innovative. Acquiring developer is easy and hard at the same time. Easy because developers are very active online. Hard because there are tons of websites and blogs that are fighting for their attention. As a developer, I have clicked on very few ads. But I have almost always clicked on a good article..
All the best. tweet me @vishal_in if I can help ..
I do not know enough about your business to say whether or not you will be able to do so in a cost effective way.
I spent $100 on ads, which resulted in around 25 new subscribers. The next week, I wrote a really in depth Arduino Morse code tutorial which ended up on some social networks and netted me ~100 subs.
I'd say that Google adds for me where NOT worth the price. Generating more organic content worked better.