I notice it used frequently on this board.
I haven’t seen it used like that very much. I would say that ‘addictive’ is still the preferred usage.
I’ve noticed it in the last few years. Must be addicting, because it doesn’t go away. It does sound odd to my ear.
I just put the relevant words into googlefight.
Addicting got 7,210,000 results but addictive got 26,200,000 results.
Addictive is still dominant but that’s alot more results for addicting than I would have guessed.
“Addicting” seems to be used almost exclusively as a predicate, after forms of the verb “to be”: Man, these chocolate-covered pretzels are addicting.
“Addictive” seems to be used more as a conventional adjective, modifying another word: Morphine is one of the more addictive opiates.
Use of “addictive” in the first sentence would be understood, but may be marked as stilted to many audiences. Use of “addicting” in the second sentence would rankle stylistically to the point of not really being an option.
Additionally, there seems to be a sense that “addicting” is an all-purpose word for less-than-serious matters: Man, X-Box is friggin’ addicting! To me – and I’d bet to many American English speakers – “addictive” sounds as if it belongs firmly in the realm of the starkly clinical.
I’d agree, bordelond. If someone told me “These chocolate-covered pretzels are addictive,” I’d immediately wonder what kind of drug it was laced with. “Addicting” connotes a mere strong liking for something, while “addictive” connotes a potential for actual dependency and addiction; it’ll get you tossed into the Betty Ford Clinic.
The same for me.
I’ve never heard of ‘addicting’, so I’m putting it down to another example of the US trying to steal away my language!
“Addicting” still mildly grates on my ears. I use “addictive” even with a sentence like “That chocolate cake sure is addictive.” I never noted the connotation difference between “addictive” and “addicting,” but I guess it makes sense.
I suppose it’s better than addictivish.
It’s a loose thing … definitely still in flux. There may be a correlation with age, but I don’t have stats on hand.
Just don’t behave addictively in public. 
I’ve been hearing “addicting” a lot lately and it bugs me, but I guess it isn’t technically incorrect so I should just get over it.
Addicting is beyond grating to me - I don’t think I’d correct someone who said it, but I could never bring myself to say it. Addictive, whether it’s chocolate cake, heroin or the SDMB.
Huh. I’m Canadian and have never heard ‘addicting’. It grates.
I’m American and I’ve never heard it either. I agree; it grates.
I would love it if someone with an OED would look this up.
A linguistic prescriptivist once informed me that “addictive” should be used only to describe something liable to become the subject (not object) of an addiction. E.g. “He was diagnosed with a highly addictive personality.” Any other use, he said, is non-standard.*
Whereas “addicting” should be used to describe items likely to inspire addiction. E.g. “Tobacco companies have known for years that cigarettes are highly addicting.”
I always use these definitions of these words in case my conversation partner turns out to be an anal prescriptivist. But on the other hand, I really have no idea whether my definitions are accurate. Does anyone know if there was ever a time when these different usages were standard? In any case, any battle there might be to preserve the old definitions of these words is long over.
*As always, I am not trying to start a prescriptive/descriptive linguistic debate here. If you must, please take it to another thread.