Ben Reilly was a clone of
Spiderman who appeared early on (issue 149) in volume 1 of The
Amazing Spiderman. Despite the fact he died in his debut issue he came back in the early 90s as
Scarlet Spider and temporarily replaced
Peter Parker as
Spidey in the
Clone Saga. Reilly was killed in a fit of cliches by the
Green Goblin and Parker redonned the spider costume.
The above paragraph is the bare bones in what was perhaps the worst thing to happen to Spiderman in his (albeit fictional) existence. The best anyone has to say about it is it made readers appreciate that Peter Parker, student and employee of the Daily Bugle is as integral to Spiderman as webslinging- although this did not need clearing up for most readers.
The story was a debacle from beginning to end (Wizard Magazine relentlessly hyped it though - hmmm). It was the mid nineties. Marvel had seen their market share wither with the distinguished competition and Image Comics making headway. They decided to do an Age Of Apocalypse or Death Of Superman style epic for Spidey with the hope that this could gather widespread recognition outside the field of comics. They began with a weak premise - The Marvel universes' science must vary from our own in that dead people regularly get up and continue unfettered (Elektra, Wolverine and Red Skull to name three have all died and gotten better) in a fit of between questionable and downright shoddy storytelling. While Elektra's death and resurrection was a classic storyline the Clone Saga (excuse the expression) died on its' arse as they say in Glasgow. The storyline was awful for several reasons but as far as Reilly is concerned the character was not a patch on Parker and did not develop in interesting ways. It also served to alienate thousands of readers who voted with their feet; Spidey sales in this period plummeted to a fraction of what they were before the mess began.
The sad thing about Ben Reilly is that many fans feel that given time he would have turned into an OK supporting character akin to Robin in Batman. There is also a view that a few whining fanboys loud protests at the removal of Parker as Spidey ruined Reilly. While the first view is barely worth arguing - it is safe to say we will never know as Reilly has been indefinitely shelved - the second widely held opinion does not stand up to discussion for the reason that nobody cared about the scarlet spider storyline come its' conclusion because it was a flawed story that amounted to a publicity stunt more than a good comic. In closing the Reilly/clone calamity showed that not even Mighty Marvel can get away with second rate publications all of the time.
In the defence of some of the guilty parties (Mike Wieringo, John Romita Junior - two artists involved in this quagmire) amends were eventually made and some of them even (the above two for example) started producing quality work. Most of the editors and writers responsible (no names mentioned) have since vanished from popular/mainstream comics. Whether this is entirely a bad thing is the subject of debate.