Just don't request payment (or don't request much) and you'll be hired. You'll still be hired if you request a lot of gold, too, but you won't necessarily get anything for it.
Send applications for the "underdog" and the attacking side, as well. You'll be more prone to be selected if it looks like your team is not favored, and people typically rush to defend others if the fight seems fair. Be sure that you watch carefully to see if you are accepted, and when you are, check the pre-battle thingy (new tab that shows up) for possible teamspeak or ventrilo information. If the roster is full you will often be dropped from it to make room for others, if you're not present in the chat before the fight.
That has been my experience- generally speaking. And yes, you can easily win a battle against 700 new player's troops if your side of 49 tickets actually has equipment.
Keep in mind you are fighting with your employer's tickets (Which they bought, and continue to pay for - i.e. army/soldiers) as well as their equipment (which they've paid for, and they lose when you spawn with it and die.) So, if you generally do well, you will often receive payment, but if you do poorly, you shouldn't expect anything.
You get a fair bit of EXP for your character while you fight in strategus battles, so that right there is a good incentive to just show up and fight.
