I'm not sure I've ever seen a decent job advertised that said "A+ Certification Highly Preferred." I suppose it's useful it you want to work at Circuit City or Best Buy and install people's new HDDs or Video Cards for them...
Not to bash CompTIA as they definitely fill a vendor-generic certification niche, but I rarely see any jobs preferring any of their "+" certifications and very few employers that brag about having x percent of staff "+" certified in this or that.
I have seen a zillion companies list A+ Preferred - its usually the first listing of about 5 preferred certifications most IT employers are looking for. Now some dont list it because they assume you have it if you are MCSE or MCSA, because its pretty much the first thing you should get.
If you really want to be marketable, get all the way to MCSA/MCSE, then go to college for an CS Degree. You can get credit for some of courses you took in cert path, plus having gone through the cert process you know most of the Degree related subjects. Its just a matter of passing Math, Eng, Hist, Science ..etc.