Let me put it this way. It is to the surfer's benefit for each webmaster's site to be more comprehensive and more authoritative (that is, that it give a fuller picture of its author, so that the surfer can have the information necessary to judge the quality of the information given.
So that's what we as editors want to see. On the other hand, if it is in the author's interest to promote his content, then he'll either link it all together as appropriate (either that, or he's just a sneaky spammer, and we don't care WHAT happens to him, so long as it it painful.)
Now, if the author is doing an honest job of exposing the material to people interested in (say) web development technologies, then the ODP can do its job most effectively -- that is, expose the author -- and, for tutorial material that is "exceptional" -- not the top twenty percent, or the top ten percent, but far and away the top one percent) -- editors will be able to find it and deeplink it as necessary on our own.
As a quick, simple answer, try this -- it really works. Make one site that fully, comprehensively, answers the question: "Who are you, what do you know, what have you done, what would you do for money?"
We want to link to that site. And as you learn, as you do new things, you want to add to it.
Beyond that, we do what we think our surfers would find most useful. That's editorial judgment, and it's not always reduceable to simplistic rules. In general, it means we tend to list the deeplinks we need most, not the deeplinks you want most. And that means we are usually quicker to add new sites than to delete no-longer-exceptional but still mildly useful deeplinks. (The net effect is to give a lasting reward to people who pioneer particular kinds of online content -- and we don't think that's a BIT unfair!)
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