Beware of some of these offers -- they often say XXX days free trial and then YYY per month -- and YOU HAVE TO SAY YOU WANT TO TERMINATE or your credit card will be charged automatically. -- THE ONUS IS ON YOU TO CANCEL. Shouldn't be but there it is.
Consumer groups should go after these types of deals but the Internet being an International facility - makes enforcement rather difficult especially if the contract is being serviced from some of the more "dodgier Countries".
If I were you -- NEVER EVER pay a SUBSCRIPTION of any sort on the Internet by credit card.
By all means PURCHASE 1-off items / travel etc. via credit card but NEVER use a standard credit card for a subscription or Monthly fees via the Internet.
If you MUST go for these type of deals use a "Pre paid" DEBIT / CREDIT Card -- and if you feel you might be getting stung just empty the card so there's no money left on it.
You can get these types of "Pre Pay" debit / credit cards all over the place -- very handy too as there's no stupid Credit checks or anything and you can top them up at your convenience.
You can get SEVERAL of these so emptying one doesn't mean you can't use another one for something else and these don't go through Experiian / Equifax or any of these other credit reference agencies so there's no data held about you which 3rd parties can get hold of --that's what I like. !!
For instance here's a UK based one which I use when I'm in London -- others in different countries are available too. Cashplus Prepaid Card – the prepaid credit card alternative with no credit checks | Cashplus
Please though as for ANY Financial product PLEASE Read all the small print though before applying for these cards as they *might* not be suitable for some people.