From the Applicant's Perspective
I've tend to use several totally orthogonal techniques when sending applications. At times I would be downright "bulk-oriented" in my approach, at others I would efficiently target just a few select companies and make sure to write a custom resume and cover letter with a lot of insight about their business in it.
It depends what your end goal is:
- do you need a job, any job, quick?
- do you need your dream job for life?
The (E-)Mail Blast Technique
The first approach means you'll need to deal with hundreds of responses and requests, so be sure to not get names mixed up. It's not a bad approach, as you effectively weed out a lot of potential employers, and by having a few different cover letters and resumes for several roles you are interested in, you can send a lot of applications in little time. And the sheer number of responses that you get back increases the chances of a positive one. And if it doesn't work, and as long as your application was correct, not ridden with typos and bad grammar or addressing the wrong person or referring tot he wrong application and being really totally generic, you'll probably still be in their system. You have a foot in the door, and some contacts for later. Ok, maybe not a foot, but a toe.
Do not abuse this and push it so far as to get blacklisted!! Covering a lot of ground doesn't mean annoying people and sending botched applications.
The Surgical Strike
The second approach, I've used to target either dream positions OR small startups. Startups are usually looking for people with vague skillsets, have no clue how to hire people and conduct interviews, and are easily impressed, especially if they haven't found their core components yet (like their CTO or technical lead). So when you show up with a good resume with the keywords they want (that they might only vaguely understand based on an initial market research), and submit an extensive cover letter where you show that you've researched their activities, thought about new ways to improve what they already have, and can link recent or upcoming news to potential benefits or threats for their business, they'll be all hears, and you appear in a very positive light, and are on your way to an interview. And as mentioned above, they usually aren't so good at interviewing, being new to the field or not having the time to prepare for interviews, as their lifes are quite busy. So come very prepared again. It actually doesn't take too long. You can research a company decently in 2 hours. In 4 hours, you can have a solid background knowledge about them and their industry, and a solid case to help them improve.
I've done this successfully a few times, targeting very precisely some startups and I got 100% of positive returns. Truely. I only targeted a few, which were still in their infancy and prototyping stage, and they all contacting me back to meet and offer me the position. So you might still have the luxury of choice.
From the Recruiter's Perspective
I am actually also on the other side of the fence quite often, and have recruited people for several types of positions in different companies, acting a few times just as a mere complementary interviewer and sometimes as the recrtuiment lead for some projects.
About CVs / Resumes
What I can tell, from my experience, is that I will probably look at generic resumes (I need the "good generic" kind, not the cvtemplate.com kind) with a bit of disdain but it never really affected my decision if they didn't contain at herd of typos and bullsh*it. The reason for that is that we get a lot of even worse-looking resumes from recruitment agencies, who insist on using their dumbed-down formats or completely screw up the applicant's original design. So I've gotten used to go past that.
It's just a sheet of paper, the form is irrelevant. It's the content that matters. In terms of presentation, the quality and clarity of the writing go way further than any kind of pretty-printing or custom targeting.
About Cover Letters
Now, cover letters are a different story. I would still not care about form and design, and I'd prefer to see one that is obviously partially taken from a template if only for the formal fioritures over a badly-written one. But at the end of the day (well, or of the letter), what matters is: did the letter bring in any value? If yes, bonus points for the guy. If not... depends if it was requested by me (I don't request cover letters). If none were supplied, there are no "negative" points in my mind.
Having one supplied, which is concise, quick and easy to read and seems to show that you, bluntly punt, give a sh*t about your future job, is definitely a strong point that shows motivation and hard-work. But I don't take offense of mediocre ones.
I've received (and sent...) some where names got mixed up. I usually chuckle, and still look at it. There's no point in dismissing the applicant for that.
It might look strange, but I'm rather loose on this issue, while I'm quite strict on others like screening and test results. Primarily because the CV and cover-letter is mostly a social dance than a real tool. It's the base to weed out the exceptionally crap applicants. It doesn't help in any way to identify the good or exceptionally good applicants.
Bottom Line: Both approaches work. It's difficult to say whether one is more efficient than the other. It really depends on the quality of your resume and on the companies you target, and probably on your industry as well.
Also, there are no magic tricks: even the bulk-approach, to be efficient, requires some upfront work to get it going the right way. I doubt that brainless spamming of recruiters with completely crap resumes coming from an online template site will work or be beneficial in any way.