I'm sure you know all of this already, but, when I was in Advertising, the best thing we could do to gain people and $$ is to show consistency, eyeballs on the piece, and value...Beyond that it was persistence, grouping, placement and package pricing. Longevity helped too, but that's difficult with a new relatively unproven model of publictation. (No matter how cool it is!) :-)
Contracts always help...
Bonus placement, or bennies help...
Buy 3 get (whatever) free....
Readership promotes advertising. Contests promote readership. Sponsorships promote contests, Advertising helps sponsorships...its a vicious circle but one that worked well for me when I was classified manager.
We fought the same battle with publication that shall remain nameless. We had to always prove to advertisers our quality, service, pricing WAS better than the competition, because of we offered (daily consistency, in-house design, innovative ideas and better service). Apples and Oranges when comparison shopping.
Make fliers regarding comparison shopping for advertisers,
Offer Time sensitive ad specials
Run contests and readership promos (Like V-day..it was fun, it got eyeballs on the piecs, and created momentum)
Thanks and I hope this helps!
Again...I'm sure I'm preaching to the choir here...