Most trade magazines of that era were pretty similar in size and number of ads , eg. PC Magazine. Pre-Internet they were one of the only ways to keep up with industry news, topics and products.
Then there was computer shopper...man I'd get 8 months out of one of those just paging through and dreaming
There were, and still are, a number of magazines in the electronics industry, EDN, for example, that were available for free to engineers that were 75% ads with a few articles. The publishers and advertisers expected the articles to draw the engineers who would be the ones to spec components for their current designs.