Freeman (1978) suggested that there were 6 strategies based on the speed and timing of entry of firms into new business areas (the first 4 being tech focused):
Aim for technology and Market leadership. For example Dropbox or RackSpace.
Behind offensive firm in market, can learn from their mistakes or take different parts of the market. For example Nook following the Kindle.
Behind tech leaders, takes advantage of licensing, geography and costs. For example Reuters new business providing farmers with crop price information via text.
Satellite to other firms, highly dependent on customer for technology. Such as game/aps developers for Facebook/iPhone (e.g. Zynga).
Little if any tech involved, changes only due to fashion, often hand made. For example traditional pottery like Paul Jessop.
Realises new niche opportunity, but not based on R&D or tech, just something no-one has thought of before. For example Snuggie Blankets (basically a blanket with arms)