General Lifespan of a Digital Camera:
If Point & Shoot: My friends and my own experience (2x) is about 3000-8000 shots and you'd most likely run in one servicing, minor or major issue. 3rd tiers/OEM digicams are another story altogether. My personal experience is a service run-in after the first 6-10mths with normal weekend/some weekday use. But from my associates exp, they have already written off the unit before it has even met back its maker, usually becos of frustration and increased product expectation, peer pressure another BIG factor. the poor OEMs get cast aside so soon that they still work well after many years! how ironic. just like what they say in BKK, a beautiful woman by the counter is more likely to be inflicted with a disease than an average one.
If DSLR: Checked with a few brand techies, assuming manufacturing flaws/bugs aside, usually the first to get serviced is the Shutter, flw by the CCD/Circuit Board. A prosumer styled DSLR shutter can last say 30,000+- (more on the +++ side). for comparision, D70 is unofficial at 30,000+ vs the pro-devices at 100,000 and above. Here there is no direct inference, just the technies their personal assessment thru their work. there aft, calibrations, alignments, fine-tune, cleaning seem to happen every other month.
That said, the same techies advise that the more you expose the CCD, for longer periods, aka long exposure shots, or continuously slam the shutter day in day out, and of course the standard impact and knock-overs, these will deteriorate the camera further and faster, be it P&S or DSLR, cos' the latter had more of these factored in in its design/manufacture process. aside that your new toy is a complete lemon at point of purchase, deteriorations usually comes in form of funny sounds, increased artifacts in pics (ie noise), overexposure or underexposure in normal day-to-day shots, flash failure or inconsistency, or simply here drop off, there slipped out... the best of all, you might experience all these in the same period off the same cam... just like ME...2 cameras!
On the other hand, think from a recent article, Digicam LCDs are made to last 3yrs?..my personal experience is they NEVER did die on me/my friends yet, the only exception is that they exhibit flaws (tinting/dead/coloured pixels) at the buying onset (hence exchange, if possible), or they get cracked by accidental impacts, again usually in the first year due to recklessness or inexperience! From the techies and other parts quoted, 1.5-8" LCD servicing would be ard $200++, and no there is only one size, thats the one your camera is designed to come with in the first place.
ultimately my personal expectation for a new cam (a reasonably respectable one la) is 2yrs++ coming to 3 max, with good regular care. i am not likely to pay for any major overhaul, lest the overhaul is 1/3 the price of a new cam (3yrs gauge mah). thereafter the big 3, i am prepared for it to die on me at the next sat outing.
anyone who likes to comment/amend, pls feel free.