The ads tend to give the impression that anybody can get instant credit online. This is actually not the case. The original idea of instant approval for credit card offers was targeted at people who have a very good credit rating. The regulations in this regard have loosened somewhat in recent years.. even if your credit rating is not perfect you still may be able to get approved instantly for a credit card online.
One of the major determining factors is that the credit card company have to be able to access your credit rating instantly. One of the things that will go in your favor is that there is massive competition in the credit market and as a result of this quite a few have the companies have relaxed their need for an almost perfect credit rating.
So, even if your credit history is not perfect, it is possible to get approved online for an instant credit card. Really, the only way to find out for sure if you are eligible is to apply but please bear in mind that if you have had some difficulties in the past which are credit that this may cause your application to be declined because while the criteria applied by the companies has become more relaxed in recent times this type of instant approval is still not necessarily the easiest to get if you have a somewhat sketchy credit past.