My experiences of dating agencies was somewhat woeful. I think that even tho I'm a good lookin' fella (my words, not theirs. Lol), women couldn't get past the long hair I had at the time. It was the 'good' sort of long hair mind, women were soooo jealous!!
You must remember women don't do originality (maybe that's why they have slightly looser rules on these things). I remember about 90% of the women going by a profile name which was some variant/reference of/to Bridget Jones. Ie, BridgetJones69, BridgetJonesLondon, LookingForDarcy123...etc. Yaaawwwn!! Also, practically every profile ended with "...or a night in with a video & a bottle of wine."
I used to show my profile blurbs to friends at work, and they'd say they were works of art. I used to spend hours/days dreaming them up (I did one littered with Queen song titles for a laugh, if I find it I'll post it for ya). It's just that women couldn't get past the photo, so they probably never read them!

My advice (from experience) is this:
Don't put a photo on, or if you do make it B&W or make sure you're gorgeous.
Don't be original, just say the basics & maybe drop in the odd chick-flick title.
Don't lie, but stretch that thruth til it hurts! (You're not a shelf stacker, you're a stock maintenance technician). Lol.
Keep it short-ish, they have short attention spans. Bless 'em!
Mention how much you adore the children in your life, ie nieces, nephews, next door's little 'darlings'. Funnily enough, this sort of talk endears them to you, but saying you'd love your own has them running away like the wind.
About them:
If they say they're "mad" or "crazy!!", they're either ditch-water dull or are genuinely certifiable.
If they use "My friends describe me as...", read no further and move on! If she can't think of something to type on a profile, you won't get a conversation out of her!
Single women have cats (note the plural).
They lie about their physical appearance, knocking off at least one dress size. Large women avoid that concept altogether by calling themselves 'medium' or 'average' build. (You could use that to your advantage depending on your preference to women's sizes obviously)
Despite what they say or have experienced, women NEVER change their 'type'!! If you don't resemble their last 3 boyfriends, you ain't got a prayer!

Hope that's of some use to you, and be careful...it's a jungle out there! Lol.
Old geeks don't die, we just incur a fatal exception!