Massaging your head will help, but I'd say to do it longer than 5 minutes, it also depends on what you're using to massage your head. Massaging helps as it promotes circulation to promote growth, get into the habit of massaging as often as you can, before washing your hair and also massage during washing your hair. I like to massage a few drops of rosemary essential oil into my scalp before washing my hair, as rosemary is believed to stimulate hair growth - ideally massage using oils at least half an hour before washing, or better still leave overnight as the oils will also help improve condition of your hair, which is also important in hair growth. Another suggestion is to massage monistat into your scalp, yes it's a yeast infection cream, but it contains some of the same chemicals as rogaine so stimulates hair growth only without costing the earth.
It's IMPOSSIBLE to say how much your hair will grow, depends on you, what stage of growth your hair is in, health, diet, how you treat your hair, even down to weather. Everyone is different too, so our hair all grows at different strengths.
General tips I always give to questions like this are thus...
Try going without shampoo - still wash your hair but use less harsh cleansers - shampoo is a harsh detergent that strips away hairs natural oils leading to damage as well as causing your scalp to produce extra oil to replace what is removed making hair greasy, if you stop using shampoo your hair will be much healthier, stronger, shiny, easier to manage, it won't get greasy as fast, and healthier hair will grow better. There are different ways to wash hair without shampoo, I recommend conditioner-only/curly girl method, for this you simply use conditioner to wash hair with as this has enough detergent to cleanse but won't strip hair of natural oils as shampoo would. Seriously, don't be scared to try it as you're guaranteed better hair. You can read about curly girl method here http://motowngirl.com/no_shampoo.php and read more about shampoo damage here http://babyslime.livejournal.com/174054.html
It also helps to avoid chemicals as much as possible, even products that claim to improve hairs condition can be damaging - for example many split-end or smoothing treatments contain silicone, which works by coating the hair so make it look healthier, but in the long-term it causes far more damage than good to the health of your hair. Look into natural brands, silicone-free and SLS-free products, also consider home treatments like homemade hair masks. If you use dies then these will cause a lot of damage, so consider switching to henna as this will change hair colour while also being a fantastic conditioning treatment, the best place for henna is http://www.hennaforhair.com
Avoid hair dryers as overheating can damage your hair and never rub with a towel as it will damage the hair cuticles, instead leave to dry naturally or if you do use a hairdryer use protecting sprays and choose a dryer with lighter or cooler settings รยขรขโยฌรขโฌล use until your hairs 90% dry, no more. Also try using a wooden comb to brush then a hair brush with natural bristles as these are much gentler on your hair and can improve shine, another tip is to use a satin or silk pillow as this prevents hair snagging as it can on other materials.
Things such as stress or bad diet can seriously effect your hair, I saw the huge effect diet has on hair when one of my friends sadly became anorexic, the effects started showing alarmingly fast, her hair became so brittle it would literally fall apart in her hands. Don't underestimate the importance of diet, don't follow fad diets or yo-yo diet, instead keep up a good healthy diet at all times. Particularly helpful foods are oily fish like sardines, oats, nuts, seeds, guavas, papayas, and of course lots of water, using a good multivitamin will help (hair & nail vitamins aren't necessary) and also I'd recommend flax seed oil in capsule form.