I think print advertising in the technology industry only really works for brand development type marketing, and only when the budget is large enough. Spreads in industry magazines tend to be £1k-£10k a page depending on the magazine and it's readership, and these only really have any impact as part of a wider marketing programme. So imho, if you have less than £10k-£100k as your marketing budget, I suspect it's not really worthwhile.
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an example take hostingcon and cpanel. cPanel had a large stand their that would have cost a few thousand to have made, they would of paid a few hundred to attend hostingcon along with a few hundred in hotel costs for their staff that attended. How many actual sales would they have made at the event? most likely NONE, but its all about brand awareness and creating contacts