As expected, I do find the prompts for "Pay more! Download this!" in my full game that I already bought to be obnoxious. But not just because they're intruding into what should be a finished product, and not just because they may not warn you until you're well into a conversation that you can't finish this without paying money, but also because they seem so completely pointless that I can't imagine why anyone would pay extra for them other than an overabundance of money and time.
They may be more interesting when you're inside them, but the sales pitch from within the game (that is, the conversation leading up to it) does not at all make me want to find out what they're about, it just makes me want to slap the NPC for wasting my time.
On the positive side for the game, it is giving me enough leeway with character choices (and with not penalising me for passing up a large number of sidequests) that I feel able to roleplay my character concept most of the time. And the real way to sell me personally on DLC, of course, would be to offer me quests more personal to my character's motivations. How about a sidequest to carry out a clever and well-deserved revenge on that snotty elf-abusing bitch in the Denerim market? (As it is, she's the ONLY person I've pickpocketed in the game, because she deserved it.)
(Also - Bann Teagan romance mod! I guess you can sum me up in general with "the kinds of things people are likely to add as fanmods")
Such addons would appeal to smaller sections of the audience but they'd also be much smaller to make... they'd also need to be cheap. Dunno.
(I haven't attempted to access the DLC that's supposed to come with the retail copy I bought, because it claims the codes expired in April, which was before I'd even bought it.)