Optimising for search will create organic traffic - this is 'owed media' - the benefits ow owned media are that it's always there so long as you keep optimising. But a high ranking page can generate lots of revenue on autopilot for many months and years for just a couple of days research and writing time. The downsides of this is that you have to be a real expert in your field or have done so much research that you can write like one and know how to optimise to get the high rankings that will generate the traffic and revenue.
Organic is not immediate. It might take a month to get your domain authority up to a reasonable level through link-building and then each page might take a week or month to get onto page one and then after a bit of tweaking to position 1-3 (where the money's at.)
Paid is different - it's immediate. You don't own it you pay for it. It's someone else's system (ad words or Facebook) and you're buying their advertising space. The benefits of this is it can yield instant returns and is extremely flexible so you can run flash sales and offers etc.
There is a huge amount of research to suggest that the long term benefits and ROI or ROE or ROMS (or whichever metric you go for), of organic far outweigh those of paid. Because when you turn off paid media it's gone. Whereas you can't turn off organic, it's evergreen and the traffic just keeps coming.
If your questions is more about which keywords to use, traffic ones or money ones then this depends on how your site operates. But always have money in mind if you're running a business or helping someone else with theirs for a fee. The highest bid PPC keywords are clearly the ones that are going to generate more conversions and money. Because the huge google marketplace has decided that for you in a billion ways. So if it's a service business and there are people bidding on '[service] cost' then write an article about cost, price comparisons or what people are actually paying for inside the product (is it research (pharma) or the actual materials (jewellery) or the skill of the creator (art) - so that you rank for cost/price. Or even just put the cost on there. This is something lots of B2B companies don't do - and it's a conversion killer. People want to know how much something costs. Like at least a ballpark figure.
Or if you make your money with the ads network then go you may wish to go after the high traffic keywords and get the traffic so that you get paid more per ad impression. I like to go for both traffic and money. Why limit yourself to one or the other? And with traffic comes authority and lots of other benefits, you may find that a bigger site with more traffic is like a snowball and starts attracting links so you can rank better for the money terms too.
But start small. Everything starts from nothing. And there'll be niche keywords with moderate traffic and low competition and commercial intent that you can rank for to kick things off.
That's a difficult question because it's not 100% clear whether you're asking about paid vs organic or traffic keywords vs commercial intent ones.
Hope this essay helps though. Feel free to ask again if i've misunderstood.