I think it's great idea, but i think it won't work well. Multi accounts and spammer will found this site & use any way to earn free bitcoin in easy & fast way.
Just like faucet website with ads, but we don't input captcha, but search what we want.
Can be prevented easily by simply limit the IP address to a search every 2 minutes
Or add captcha for every search query

Could you see yourself ever using google again if they implemented a one search per two minute limit? That'd basically kill searchtrade.com in one fell swoop.
Agree, but i think most people here is using the search function solely for the satoshis they earned, not really searching on the engine
Not trying to be offensive here, but why choose this if you got a google search engine

At least the bot can be minimalized by using captcha security for every search query if OP don't want to put IP limit
We have bot detection in place already and it does not stop you from making searches just blocks payouts. I agree most people at this point only searching to make bitcoin but we are in process of adding more value add services for users. Google has taken 18 years to get where it is give us some time to build the service into greater value proposition for users. Thanx for your interest looking forward to more analysis from your end. Cheers