Marvel sought to capitalize on the popularity of their then-current books by presenting a series of anthology titles whose focus would be reprinted early material. Thus was born a series of titles: Marvel Tales, Marvel Super-Heroes, Fantasy Masterpieces, and Marvel Collectors' Item Classics. Square-bound, with $0.25 cover prices (as opposed to the $0.12 regular books), these editions would be 68 pages, and include a variety of interior features. Eventually these titles would reduce in page count and focus on individual features, and other reprint titles would spring up to support the displaced features. These titles included Marvel Spectacular, Marvel Double Feature, Marvel Triple Feature, Marvel's Greatest Comics, and others.
Marvel Super-Heroes (1967) was a title change from Fantasy Masterpieces (1966), which had focused on reprints of Atlas-vintage monster and supernatural stories, then Golden Age Super-heroes. The title change brought the introduction of new content along with continued Golden Age super-hero reprint stories. It thus provided a test platform for new product, notably showcasing the first appearance of Mar-Vell, aka Captain Marvel. This format held until issue #21, where the new content was dropped and the reprints switched to Silver Age material. The title at first reprinted mostly Daredevil and Iron Man (from Tales of Suspense) stories before switching to the Incredible Hulk (from Tales to Astonish) as of issue #32, which is also when the page count dropped from 68 to 32 pages, from square-bound to saddle-stitched.
Although always distributed under the Marvel Comics Group imprint, the Publisher of record in the indicia has changed several times in its history:
Issue #'s 12 - 17 : Marvel Comics, Inc.
Issue # 18 : Perfect Film & Chemical
Issue #'s 19 - 35 : Magazine Management
Issue #'s 36 - 105: Marvel Comics Group
The early publishers are a vestige of the transition from Martin Goodman's ownership as the modern-day Marvel Comics arose from its Golden Age roots in Timely / Atlas.