One of my pet peeves as it relates to media planning is when people use the expression "continuity". It is usually used in context of how many weeks or months a campaign is scheduled for. The misconception is that if you have longer blocks on your flowchart then you have more continuity. The worst offenders are those that block out a month for magazines and fool themselves into thinking they have activity for the entire month. Blocks on a flowchart do not equate to continuity of ad exposure. Continuity means people can see the ad frequently over the time period. If your monthly print R/F is in the 50/2.0 range you don't have continuity, you have fleeting impressions. Out of home media provide continuity. Properly scheduled TV and radio are continuity, but rarely does magazine advertising provide continuity of messaging.
Think about this, the time spent with most magazines is about an hour total and few issues are picked up more than 3 times by their audience. If a magazine is read within an hour (even over three occasions) and it contains around 120 pages the amount of time spent per average page is only 30 seconds. So, an ad in a monthly magazine provides the same message length as a single :30 ad in one airing of a TV program. Obviously magazines like The Atlantic, The New Yorker and The Economist have longer reading times but each page is really only looked at once. When we plan TV or radio we try to schedule 100+ weekly GRP's in order to ensure that a significant percentage of our target see/hear the ads over that week. I typically strive to achieve a 70 reach on a weekly basis with TV. Yet most planners feel that a monthly R/F of 50/2.0 is adequate for print.
The last time someone planned print for continuity was almost 20 years ago when the first Milk Mustache ads were used. Somewhere in the neighborhood of $40 million was spent by them and hundreds of insertions were scheduled. Lots of people were seeing these ads every day. This was a print plan that was scheduled like a TV campaign. I bet if weekly R/F's were run on that campaign it would be closer to what most consider effective for TV.
Don't fall into the trap of viewing a light schedule of monthly insertions as continuity of messaging. Continuity is only achieved when people have opportunities to see ads frequently over a set time period.