Like any business you need to find what converts best, building a site even if your getting a reasonable amount of visits a day doesnt mean it will automatically start converting.
Doing cheap shared hosting on a grand scale your going to need a good marketing budget or a good team willing to spread the word, alot of time and exceptional support and equipment to even make a dent and turn a profit, you'd be much better off charging more and targeting a sector of the market until your more established and the branch out, you can offer cheaper starting packages to a select few people in those sectors to gain reputation and recommendations.
Do a bit of outreach to already proven affiliates offering them above average conversion commissions to get the ball rolling.
Running a higher quality service at a higher price will mean you turn a profit on smaller number of clients but it will also mean you havent got 200 crappy coded client scripts smashing your resources to bits who expect the world for £2 and taking all of your support time.
Id much rather have 60 clients at £10 a month who have been approved and vetted than 300 at £2 a month auto sign up and setup clients who use and abuse or are too stupid to know a script from 2004 from a warez site is the issue and not the server
P.s Site is not slow for me at all, working well .