there is no assurance that the online test, unless developed and delivered by a recognized testing company, has been properly benchmarked to deliver valid results. in fact, if they're trying to sell you something [or something more], then the temptation to cheat a little on scores is high ...

True. To get a true results of your IQ, it needs to be done in the proper testing. Online test are more fun and amusing and the best they will be able to do is give you more estimate of your real IQ. Not your real IQ. The real IQ test I have done, give you a range of numbers like 120-145, and not just a single score.

I always do good on those so I'm guessing no.