Vlad Well maybe you need to optimize this area first (or maybe review your cost calculation algorithms so that you et a better picture of your actual operational cost) I don't want to sound arrogant but 1,5 cents per search seems to be a huge over estimation.
e.g my ancient at this point intel 8750h (which is in no way shape or form an optimized cpu for this workload far from it actually) at 100% constand load at 3GHz (so after turbo goes off and thermals are at an equilibrium) can perform around 75× 1010 IPS (instructions per second) while consuming 35W
1 × 1010 instructions per second (according to my online searches) is what it costs to process a search querry fo r google
(^-- this also sees exceessive to me but I assume they include overhead breaking down the querry to their cluster, spell checking, ad indexing and whatever else they do behind the scenes, in orther words not just the instructions needed to run the code that retrieves the actual useful -to the user- payload aka the results)and that also represents a 100MB of bandwidth needed.
Which means my CPU can process a single such querry in about 100-110ms (100 ms being Google's average latency target btw)
but I do you a better one lets assume it will take it 250ms.
so lets assume my ancient 8750H can process 4 querries (1000ms/250ms) instead of about 10
4 per second *60 seconds = 240 instructions per minute
240 instructions * 60 minutes = 14400 instructions per hour.
so at full load in an hour my ancient CPU would have consumed 35Watt hours, with innefficiencies introduced via the PSU and various other stepping modultions don in the VRM lets say it consumes 45wh
Lets assume an outlansdishly expensive rate of 50 cents per kwh (usually the cost of a kwh in the western worl is under 20 cents and in many places under 10 or even 5 cents per kwh)
that means that the CPU in 1 hour of load would spend 2.25 cents of electricity (using the super expensive rate which means it will spend a lot less actually)
2.25 cents or 0.0225 dollars
so 0.025 / 14400 querries (because that's how much this cpu can do per hour) = 0.0000015625 dollars...
coincidentally the "1.5" part was right but it is not 1,5 cents it is a figure multiple orders of magnitute lower...
And sure there are other costs involved such as bandwidth (Which at big contracts though gets a flat rate and is not calculated per MB but even so 1 google querry needs about 100MB so its not that much) cost of hardware and paychecks etc
But again using rational assumptions 1,5 cents seems waaaaaay overexagerated figure.
So if it is right I have an ancient laptop CPU to sell you and help you reduce your cost.
If not then you probably need to review the ways you calculating cost which in turn will help price the product better which in turn will result in higher profit due to higher demand since more users would be able to affort it.
Or in other words aim for profits of scale not how to squize more profit per individual sale.