ASO Versus Paid Search Advertisement

The main difference between App Store Optimization (ASO) and Paid Search Advertisement (PSA) is that traffic coming from ASO (organic) is free, while traffic generated from PSA is not free (as the name implies you have to pay for the ad).
Both ASO and PSA are part of your overall App Marketing campaign.
I will try to explain the other major differences between these two by using the following parameters: position in search results, cost, traffic potential, conversion and ease of use.
As of this writing, the paid search advertising is not yet implemented.  But for sure, you can expect to find Paid Search Ads above the organic results.  Where exactly your app will appear depends on a number of factors. Organic results can only appear in the middle of the listings. Whether your listing will appear in the top positions or not this depends on how optimized your app is both in terms of on-site and off-site ASO.
ASO: You can still get to the top listings if your app  is optimized for app store search engines
PSA: You can get your app on the top listings by paying a higher cost (cost unknown as of the moment)

Cost

I have mentioned in my previous blogs, the cost of PSA is not yet revealed. So far, what we all know is that ASO traffic is free and PSA is paid. And while this is true, you need to bear in mind that it still requires a lot of effort and hard work to get free traffic from the App Store. The competition is tough for almost every keyword you can search for and you really need to have a high-quality app  and a great ASO strategy get one of the top 5 positions. There are no shortcuts despite what some “ASO” companies are trying to sell you.  If you are not familiar how ASO work or don’t know anything about it then the best way to get traffic is to hire an ASO expert, like me, to do the work you.
PSA’s cost will surely depend on a number of factors. If we take for example the cost for paid advertising in the SEO World, then it would depend on the popularity of the keyword, the number advertisers who want to use it, the number of related apps that have ad positions for the particular keyword, and much more.
ASO: Cost of ASO is indirect. You cannot pay to get to the top results but you may have to pay for ASO services if you cannot do it yourself.
PSA:  You pay for which keyword(s) you want to rank.

Traffic potential

Which method can bring more traffic to your app, ASO or PSA? ASO (organic traffic) is more than PSA traffic so if you can manage to rank your app for the keywords you want, you will get much more traffic than paying for those keywords.
If on the other hand it is very difficult to rank for a certain keyword, then paying for it, may be your best option since low rankings will probably bring 0 or very little traffic for your app.
ASO: Organic traffic is continuous
PSA: PSA can boost your app’s ranking but this means that you pay more.
Conversion/Downloads
Which visitor is more likely to convert (download your app), someone coming from PSA or from organic search? If your app is highly targeted and optimized then, it is more likely to convert than a visitor coming from a paid search.
The reason is that an app can rank for different keywords (other than those you paid for) so the search visitor may not be looking exactly for the app presented in the particular search listing. On the other hand, if you run a successful PSA campaign or you have chosen the most or relevant keywords for your app and paid big bucks for it, then for sure it’s a win-win situation for you.
ASO: ASOtraffic is better than other forms of traffic
PSA: Highly optimized keywords will generate more conversions but will definitely cost more

Ease of use

Neither ASO nor PSA is easy to do if you don’t have the necessary knowledge and experience.  ASO is a process that takes a lot of time and effort. It may take months to rank for specific keywords or not rank at all.
On the hand, in order to get some good results with paid search, you need to know how it works first, or you may hire an expert, to help you in your PSA campaign, or you will lose a lot of money.
The bottom line is that you need to use both (ASO and PSA), once paid search has been implemented, as part of your App Marketing campaign. Paid search can bring you faster results so you can run a PSA campaign and test which keywords convert better and then try with ASO to rank for those keywords.
I suggest that you use Paid search when you have a high converting product or app, and use ASO when you have a limited budget to spend on marketing and advertising.
ASO may take time but the results are long lasting while with paid search when you stop paying for it, traffic will also stop.