From 1991: Titan Books celebrated a decade of publishing JUDGE DREDD and 2000AD reprint albums with this special anniversary edition of the first JD book.
The Titan albums were regularly advertised in the pages of 2000AD but, unless you happened to live near Forbidden Planet or another comic book stockest, hard to find in the real world. That gave them something of a holy grail quality... a perception enhanced by their substantial cover price (for kids) for soft cover black & white reprints (with no royalties paid to the creative teams... although they were commissioning new cover art).
It took a few more years for IPC themselves to realise that their inventory could have value in the UK. In the mid-Eighties they launched a range of BEST OF monthlies built around the back catalogue (traditionally used to take the pressure off origination budgets in the weeklies and to pad out the specials and annuals) with varying degrees of success. The 2000AD edition, later joined by a separate Dredd spin-off, ran for a decade (and a bit longer if you count the post-movie relaunches).
Titan milked the Tharg franchise as long as possible and used it as the launch pad to expand further into book publishing (including UK editions of some DC trade paperbacks as well as the original STAR TREK novels) followed by magazines, UK comics and - now - the extensive range of US format comic books.